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SCHEDULE III REAL ESTATE AND ACCUMULATED DEPRECIATION (Details) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Real Estate And Accumulated Depreciation  
Encumbrances $ 624,139us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
Initial Cost to Company  
Land 684,385us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
Buildings, Improvements & Equipment 5,072,234us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
Cost Capitalized Subsequent to Acquisition 506,215snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
Impairment (24,223)snh_RealEstateAndAccumulatedDepreciationCarryingAmountOfImpairment
Cost at the end of the period  
Land 683,979us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
Buildings, Improvements & Equipment 5,554,632us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
Total 6,238,611us-gaap_RealEstateGrossAtCarryingValue
Accumulated Depreciation 983,850us-gaap_RealEstateAccumulatedDepreciation
2184 Parkway Lake Drive, Birmingham, AL  
Initial Cost to Company  
Land 580us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkwayLakeDrive2184BirminghamALMember
Buildings, Improvements & Equipment 5,980us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkwayLakeDrive2184BirminghamALMember
Cost Capitalized Subsequent to Acquisition 2,016snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkwayLakeDrive2184BirminghamALMember
Cost at the end of the period  
Land 580us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkwayLakeDrive2184BirminghamALMember
Buildings, Improvements & Equipment 7,996us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkwayLakeDrive2184BirminghamALMember
Total 8,576us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkwayLakeDrive2184BirminghamALMember
Accumulated Depreciation 1,005us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkwayLakeDrive2184BirminghamALMember
2634 Valleydale Road, Birmingham, AL  
Initial Cost to Company  
Land 600us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ValleydaleRoad2634BirminghamALMember
Buildings, Improvements & Equipment 7,574us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ValleydaleRoad2634BirminghamALMember
Cost Capitalized Subsequent to Acquisition 903snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ValleydaleRoad2634BirminghamALMember
Cost at the end of the period  
Land 600us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ValleydaleRoad2634BirminghamALMember
Buildings, Improvements & Equipment 8,477us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ValleydaleRoad2634BirminghamALMember
Total 9,077us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ValleydaleRoad2634BirminghamALMember
Accumulated Depreciation 1,311us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ValleydaleRoad2634BirminghamALMember
2021 Dahike Drive, NE, Cullman, AL  
Initial Cost to Company  
Land 287us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DahikeDriveNE2021CullmanALMember
Buildings, Improvements & Equipment 3,415us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DahikeDriveNE2021CullmanALMember
Cost Capitalized Subsequent to Acquisition 289snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DahikeDriveNE2021CullmanALMember
Cost at the end of the period  
Land 287us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DahikeDriveNE2021CullmanALMember
Buildings, Improvements & Equipment 3,704us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DahikeDriveNE2021CullmanALMember
Total 3,991us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DahikeDriveNE2021CullmanALMember
Accumulated Depreciation 1,087us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DahikeDriveNE2021CullmanALMember
49 Hughes Road, Madison, AL  
Initial Cost to Company  
Land 334us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HughesRoad49MadisonALMember
Buildings, Improvements & Equipment 3,981us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HughesRoad49MadisonALMember
Cost Capitalized Subsequent to Acquisition 429snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HughesRoad49MadisonALMember
Cost at the end of the period  
Land 334us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HughesRoad49MadisonALMember
Buildings, Improvements & Equipment 4,410us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HughesRoad49MadisonALMember
Total 4,744us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HughesRoad49MadisonALMember
Accumulated Depreciation 1,247us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HughesRoad49MadisonALMember
200 Terrace Lane, Priceville, AL  
Initial Cost to Company  
Land 1,300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TerraceLane200PricevilleALMember
Buildings, Improvements & Equipment 9,447us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TerraceLane200PricevilleALMember
Cost Capitalized Subsequent to Acquisition 156snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TerraceLane200PricevilleALMember
Cost at the end of the period  
Land 1,300us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TerraceLane200PricevilleALMember
Buildings, Improvements & Equipment 9,603us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TerraceLane200PricevilleALMember
Total 10,903us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TerraceLane200PricevilleALMember
Accumulated Depreciation 782us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TerraceLane200PricevilleALMember
413 Cox Boulevard, Sheffield, AL  
Initial Cost to Company  
Land 394us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CoxBoulevard413SheffieldALMember
Buildings, Improvements & Equipment 4,684us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CoxBoulevard413SheffieldALMember
Cost Capitalized Subsequent to Acquisition 462snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CoxBoulevard413SheffieldALMember
Cost at the end of the period  
Land 394us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CoxBoulevard413SheffieldALMember
Buildings, Improvements & Equipment 5,146us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CoxBoulevard413SheffieldALMember
Total 5,540us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CoxBoulevard413SheffieldALMember
Accumulated Depreciation 1,428us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CoxBoulevard413SheffieldALMember
13840 North Desert Harbor Drive, Peoria, AZ  
Initial Cost to Company  
Land 2,687us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthDesertHarborDrive13840PeoriaAZMember
Buildings, Improvements & Equipment 15,843us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthDesertHarborDrive13840PeoriaAZMember
Cost Capitalized Subsequent to Acquisition 3,542snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthDesertHarborDrive13840PeoriaAZMember
Cost at the end of the period  
Land 2,687us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthDesertHarborDrive13840PeoriaAZMember
Buildings, Improvements & Equipment 19,385us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthDesertHarborDrive13840PeoriaAZMember
Total 22,072us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthDesertHarborDrive13840PeoriaAZMember
Accumulated Depreciation 7,148us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthDesertHarborDrive13840PeoriaAZMember
11209 N. Tatum Boulevard, Phoenix, AZ  
Initial Cost to Company  
Land 1,380us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NTatumBoulevard11209PhoenixAZMember
Buildings, Improvements & Equipment 6,349us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NTatumBoulevard11209PhoenixAZMember
Cost Capitalized Subsequent to Acquisition 658snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NTatumBoulevard11209PhoenixAZMember
Cost at the end of the period  
Land 1,380us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NTatumBoulevard11209PhoenixAZMember
Buildings, Improvements & Equipment 7,007us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NTatumBoulevard11209PhoenixAZMember
Total 8,387us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NTatumBoulevard11209PhoenixAZMember
Accumulated Depreciation 674us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NTatumBoulevard11209PhoenixAZMember
2444 West Las Palmaritas Drive, Phoenix, AZ  
Initial Cost to Company  
Land 3,820us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestLasPalmaritasDrive2444PhoenixAZMember
Buildings, Improvements & Equipment 6,666us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestLasPalmaritasDrive2444PhoenixAZMember
Cost at the end of the period  
Land 3,820us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestLasPalmaritasDrive2444PhoenixAZMember
Buildings, Improvements & Equipment 6,666us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestLasPalmaritasDrive2444PhoenixAZMember
Total 10,486us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestLasPalmaritasDrive2444PhoenixAZMember
Accumulated Depreciation 667us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestLasPalmaritasDrive2444PhoenixAZMember
6001 E. Thomas Road, Scottsdale, AZ  
Initial Cost to Company  
Land 941us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EThomasRoad6001ScottsdaleAZMember
Buildings, Improvements & Equipment 8,807us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EThomasRoad6001ScottsdaleAZMember
Cost Capitalized Subsequent to Acquisition 1,066snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EThomasRoad6001ScottsdaleAZMember
Cost at the end of the period  
Land 941us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EThomasRoad6001ScottsdaleAZMember
Buildings, Improvements & Equipment 9,873us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EThomasRoad6001ScottsdaleAZMember
Total 10,814us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EThomasRoad6001ScottsdaleAZMember
Accumulated Depreciation 4,712us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EThomasRoad6001ScottsdaleAZMember
7090 East Mescal Street, Scottsdale, AZ  
Initial Cost to Company  
Land 2,315us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMescalStreet7090ScottsdaleAZMember
Buildings, Improvements & Equipment 13,650us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMescalStreet7090ScottsdaleAZMember
Cost Capitalized Subsequent to Acquisition 5,172snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMescalStreet7090ScottsdaleAZMember
Cost at the end of the period  
Land 2,315us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMescalStreet7090ScottsdaleAZMember
Buildings, Improvements & Equipment 18,822us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMescalStreet7090ScottsdaleAZMember
Total 21,137us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMescalStreet7090ScottsdaleAZMember
Accumulated Depreciation 6,206us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMescalStreet7090ScottsdaleAZMember
17225 Boswell Blvd., Sun City, AZ  
Initial Cost to Company  
Land 1,189us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoswellBlvd17225SunCityAZMember
Buildings, Improvements & Equipment 10,569us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoswellBlvd17225SunCityAZMember
Cost Capitalized Subsequent to Acquisition 879snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoswellBlvd17225SunCityAZMember
Cost at the end of the period  
Land 1,189us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoswellBlvd17225SunCityAZMember
Buildings, Improvements & Equipment 11,448us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoswellBlvd17225SunCityAZMember
Total 12,637us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoswellBlvd17225SunCityAZMember
Accumulated Depreciation 5,572us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoswellBlvd17225SunCityAZMember
14001 W. Meeker Boulevard, Sun City West, AZ  
Initial Cost to Company  
Land 395us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WMeekerBoulevard14001SunCityWestAZMember
Buildings, Improvements & Equipment 3,307us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WMeekerBoulevard14001SunCityWestAZMember
Cost Capitalized Subsequent to Acquisition 0snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WMeekerBoulevard14001SunCityWestAZMember
Cost at the end of the period  
Land 395us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WMeekerBoulevard14001SunCityWestAZMember
Buildings, Improvements & Equipment 3,307us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WMeekerBoulevard14001SunCityWestAZMember
Total 3,702us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WMeekerBoulevard14001SunCityWestAZMember
Accumulated Depreciation 1,115us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WMeekerBoulevard14001SunCityWestAZMember
2500 North Rosemont Boulevard, Tucson, AZ  
Initial Cost to Company  
Land 4,429us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRosemontBoulevard2500TucsonAZMember
Buildings, Improvements & Equipment 26,119us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRosemontBoulevard2500TucsonAZMember
Cost Capitalized Subsequent to Acquisition 4,287snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRosemontBoulevard2500TucsonAZMember
Cost at the end of the period  
Land 4,429us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRosemontBoulevard2500TucsonAZMember
Buildings, Improvements & Equipment 30,406us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRosemontBoulevard2500TucsonAZMember
Total 34,835us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRosemontBoulevard2500TucsonAZMember
Accumulated Depreciation 11,180us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRosemontBoulevard2500TucsonAZMember
710 N. Euclid, Anaheim, CA  
Initial Cost to Company  
Land 2,850us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NEuclid710AnaheimCAMember
Buildings, Improvements & Equipment 6,964us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NEuclid710AnaheimCAMember
Cost Capitalized Subsequent to Acquisition 737snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NEuclid710AnaheimCAMember
Cost at the end of the period  
Land 2,891us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NEuclid710AnaheimCAMember
Buildings, Improvements & Equipment 7,660us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NEuclid710AnaheimCAMember
Total 10,551us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NEuclid710AnaheimCAMember
Accumulated Depreciation 1,239us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NEuclid710AnaheimCAMember
1350 S. El Camino Real, Encinitas, CA  
Initial Cost to Company  
Land 1,510us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SElCaminoReal1350EncinitasCAMember
Buildings, Improvements & Equipment 18,042us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SElCaminoReal1350EncinitasCAMember
Cost Capitalized Subsequent to Acquisition 377snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SElCaminoReal1350EncinitasCAMember
Cost at the end of the period  
Land 1,510us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SElCaminoReal1350EncinitasCAMember
Buildings, Improvements & Equipment 18,419us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SElCaminoReal1350EncinitasCAMember
Total 19,929us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SElCaminoReal1350EncinitasCAMember
Accumulated Depreciation 3,141us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SElCaminoReal1350EncinitasCAMember
47201 Lakeview Boulevard, Fremont, CA  
Initial Cost to Company  
Land 3,200us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewBoulevard47201FremontCAMember
Buildings, Improvements & Equipment 10,177us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewBoulevard47201FremontCAMember
Cost Capitalized Subsequent to Acquisition 227snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewBoulevard47201FremontCAMember
Cost at the end of the period  
Land 3,200us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewBoulevard47201FremontCAMember
Buildings, Improvements & Equipment 10,404us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewBoulevard47201FremontCAMember
Total 13,604us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewBoulevard47201FremontCAMember
Accumulated Depreciation 827us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewBoulevard47201FremontCAMember
47211/47215 Lakeview Boulevard, Fremont, CA  
Initial Cost to Company  
Land 3,750us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewBoulevard47211And47215FremontCAMember
Buildings, Improvements & Equipment 12,656us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewBoulevard47211And47215FremontCAMember
Cost Capitalized Subsequent to Acquisition 142snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewBoulevard47211And47215FremontCAMember
Cost at the end of the period  
Land 3,750us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewBoulevard47211And47215FremontCAMember
Buildings, Improvements & Equipment 12,798us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewBoulevard47211And47215FremontCAMember
Total 16,548us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewBoulevard47211And47215FremontCAMember
Accumulated Depreciation 1,028us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewBoulevard47211And47215FremontCAMember
47900 Bayside Parkway, Fremont, CA  
Initial Cost to Company  
Land 4,580us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BaysideParkway47900FremontCAMember
Buildings, Improvements & Equipment 10,370us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BaysideParkway47900FremontCAMember
Cost Capitalized Subsequent to Acquisition 852snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BaysideParkway47900FremontCAMember
Cost at the end of the period  
Land 4,580us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BaysideParkway47900FremontCAMember
Buildings, Improvements & Equipment 11,222us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BaysideParkway47900FremontCAMember
Total 15,802us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BaysideParkway47900FremontCAMember
Accumulated Depreciation 892us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BaysideParkway47900FremontCAMember
577 South Peach Street, Fresno, CA  
Initial Cost to Company  
Land 738us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthPeachStreet577FresnoCAMember
Buildings, Improvements & Equipment 2,577us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthPeachStreet577FresnoCAMember
Cost Capitalized Subsequent to Acquisition 188snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthPeachStreet577FresnoCAMember
Cost at the end of the period  
Land 738us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthPeachStreet577FresnoCAMember
Buildings, Improvements & Equipment 2,765us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthPeachStreet577FresnoCAMember
Total 3,503us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthPeachStreet577FresnoCAMember
Accumulated Depreciation 1,741us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthPeachStreet577FresnoCAMember
6075 N. Marks Avenue, Fresno, CA  
Initial Cost to Company  
Land 880us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMarksAvenue6075FresnoCAMember
Buildings, Improvements & Equipment 12,751us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMarksAvenue6075FresnoCAMember
Cost Capitalized Subsequent to Acquisition 322snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMarksAvenue6075FresnoCAMember
Cost at the end of the period  
Land 880us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMarksAvenue6075FresnoCAMember
Buildings, Improvements & Equipment 13,073us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMarksAvenue6075FresnoCAMember
Total 13,953us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMarksAvenue6075FresnoCAMember
Accumulated Depreciation 2,205us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMarksAvenue6075FresnoCAMember
24552 Paseo de Valencia, Laguna Hills, CA  
Initial Cost to Company  
Land 3,172us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PaseoDeValencia24552LagunaHillsCAMember
Buildings, Improvements & Equipment 28,184us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PaseoDeValencia24552LagunaHillsCAMember
Cost Capitalized Subsequent to Acquisition 1,911snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PaseoDeValencia24552LagunaHillsCAMember
Cost at the end of the period  
Land 3,172us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PaseoDeValencia24552LagunaHillsCAMember
Buildings, Improvements & Equipment 30,095us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PaseoDeValencia24552LagunaHillsCAMember
Total 33,267us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PaseoDeValencia24552LagunaHillsCAMember
Accumulated Depreciation 14,688us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PaseoDeValencia24552LagunaHillsCAMember
1642 West Avenue J, Lancaster, CA  
Initial Cost to Company  
Land 601us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestAvenueJ1642LancasterCAMember
Buildings, Improvements & Equipment 1,859us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestAvenueJ1642LancasterCAMember
Cost Capitalized Subsequent to Acquisition 3,071snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestAvenueJ1642LancasterCAMember
Cost at the end of the period  
Land 601us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestAvenueJ1642LancasterCAMember
Buildings, Improvements & Equipment 4,930us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestAvenueJ1642LancasterCAMember
Total 5,531us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestAvenueJ1642LancasterCAMember
Accumulated Depreciation 2,313us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestAvenueJ1642LancasterCAMember
8631 West 3rd Street, Los Angeles, CA  
Initial Cost to Company  
Land 24,640us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West3rdStreet8631LosAngelesCAMember
Buildings, Improvements & Equipment 88,277us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West3rdStreet8631LosAngelesCAMember
Cost Capitalized Subsequent to Acquisition 3,345snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West3rdStreet8631LosAngelesCAMember
Cost at the end of the period  
Land 24,640us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West3rdStreet8631LosAngelesCAMember
Buildings, Improvements & Equipment 91,622us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West3rdStreet8631LosAngelesCAMember
Total 116,262us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West3rdStreet8631LosAngelesCAMember
Accumulated Depreciation 9,320us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West3rdStreet8631LosAngelesCAMember
8635 West 3rd Street, Los Angeles, CA  
Initial Cost to Company  
Land 24,640us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West3rdStreet8635LosAngelesCAMember
Buildings, Improvements & Equipment 90,352us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West3rdStreet8635LosAngelesCAMember
Cost Capitalized Subsequent to Acquisition 3,454snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West3rdStreet8635LosAngelesCAMember
Cost at the end of the period  
Land 24,640us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West3rdStreet8635LosAngelesCAMember
Buildings, Improvements & Equipment 93,806us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West3rdStreet8635LosAngelesCAMember
Total 118,446us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West3rdStreet8635LosAngelesCAMember
Accumulated Depreciation 9,540us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West3rdStreet8635LosAngelesCAMember
1319 Brookside Avenue, Redlands, CA  
Initial Cost to Company  
Land 1,770us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrooksideAvenue1319RedlandsCAMember
Buildings, Improvements & Equipment 9,982us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrooksideAvenue1319RedlandsCAMember
Cost Capitalized Subsequent to Acquisition 255snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrooksideAvenue1319RedlandsCAMember
Cost at the end of the period  
Land 1,770us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrooksideAvenue1319RedlandsCAMember
Buildings, Improvements & Equipment 10,237us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrooksideAvenue1319RedlandsCAMember
Total 12,007us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrooksideAvenue1319RedlandsCAMember
Accumulated Depreciation 1,725us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrooksideAvenue1319RedlandsCAMember
110 Sterling Court, Roseville, CA  
Initial Cost to Company  
Land 1,620us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SterlingCourt110RosevilleCAMember
Buildings, Improvements & Equipment 10,262us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SterlingCourt110RosevilleCAMember
Cost Capitalized Subsequent to Acquisition 351snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SterlingCourt110RosevilleCAMember
Cost at the end of the period  
Land 1,620us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SterlingCourt110RosevilleCAMember
Buildings, Improvements & Equipment 10,613us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SterlingCourt110RosevilleCAMember
Total 12,233us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SterlingCourt110RosevilleCAMember
Accumulated Depreciation 1,785us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SterlingCourt110RosevilleCAMember
1371 Parkside Drive, San Bernardino, CA  
Initial Cost to Company  
Land 1,250us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParksideDrive1371SanBernardinoCAMember
Buildings, Improvements & Equipment 9,069us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParksideDrive1371SanBernardinoCAMember
Cost Capitalized Subsequent to Acquisition 686snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParksideDrive1371SanBernardinoCAMember
Cost at the end of the period  
Land 1,250us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParksideDrive1371SanBernardinoCAMember
Buildings, Improvements & Equipment 9,755us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParksideDrive1371SanBernardinoCAMember
Total 11,005us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParksideDrive1371SanBernardinoCAMember
Accumulated Depreciation 2,294us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParksideDrive1371SanBernardinoCAMember
16925 & 16916 Hierba Drive, San Diego, CA  
Initial Cost to Company  
Land 9,142us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HierbaDrive16925And16916SanDiegoCAMember
Buildings, Improvements & Equipment 53,904us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HierbaDrive16925And16916SanDiegoCAMember
Cost Capitalized Subsequent to Acquisition 10,688snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HierbaDrive16925And16916SanDiegoCAMember
Cost at the end of the period  
Land 9,142us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HierbaDrive16925And16916SanDiegoCAMember
Buildings, Improvements & Equipment 64,592us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HierbaDrive16925And16916SanDiegoCAMember
Total 73,734us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HierbaDrive16925And16916SanDiegoCAMember
Accumulated Depreciation 23,320us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HierbaDrive16925And16916SanDiegoCAMember
3030 Science Park, San Diego, CA  
Initial Cost to Company  
Land 2,466us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3030SanDiegoCAMember
Buildings, Improvements & Equipment 46,473us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3030SanDiegoCAMember
Cost at the end of the period  
Land 2,466us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3030SanDiegoCAMember
Buildings, Improvements & Equipment 46,473us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3030SanDiegoCAMember
Total 48,939us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3030SanDiegoCAMember
Accumulated Depreciation 6,293us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3030SanDiegoCAMember
3040 Science Park, San Diego, CA  
Initial Cost to Company  
Land 1,225us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3040SanDiegoCAMember
Buildings, Improvements & Equipment 23,077us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3040SanDiegoCAMember
Cost at the end of the period  
Land 1,225us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3040SanDiegoCAMember
Buildings, Improvements & Equipment 23,077us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3040SanDiegoCAMember
Total 24,302us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3040SanDiegoCAMember
Accumulated Depreciation 3,125us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3040SanDiegoCAMember
3050 Science Park, San Diego, CA  
Initial Cost to Company  
Land 1,508us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3050SanDiegoCAMember
Buildings, Improvements & Equipment 28,753us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3050SanDiegoCAMember
Cost at the end of the period  
Land 1,508us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3050SanDiegoCAMember
Buildings, Improvements & Equipment 28,753us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3050SanDiegoCAMember
Total 30,261us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3050SanDiegoCAMember
Accumulated Depreciation 3,894us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SciencePark3050SanDiegoCAMember
3530 Deer Park Drive, Stockton, CA  
Initial Cost to Company  
Land 670us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerParkDrive3530StocktonCAMember
Buildings, Improvements & Equipment 14,419us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerParkDrive3530StocktonCAMember
Cost Capitalized Subsequent to Acquisition 366snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerParkDrive3530StocktonCAMember
Cost at the end of the period  
Land 670us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerParkDrive3530StocktonCAMember
Buildings, Improvements & Equipment 14,785us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerParkDrive3530StocktonCAMember
Total 15,455us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerParkDrive3530StocktonCAMember
Accumulated Depreciation 2,495us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerParkDrive3530StocktonCAMember
537 E. Fulton Street, Stockton, CA  
Initial Cost to Company  
Land 382us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EFultonStreet537StocktonCAMember
Buildings, Improvements & Equipment 2,750us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EFultonStreet537StocktonCAMember
Cost Capitalized Subsequent to Acquisition 917snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EFultonStreet537StocktonCAMember
Cost at the end of the period  
Land 382us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EFultonStreet537StocktonCAMember
Buildings, Improvements & Equipment 3,667us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EFultonStreet537StocktonCAMember
Total 4,049us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EFultonStreet537StocktonCAMember
Accumulated Depreciation 2,024us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EFultonStreet537StocktonCAMember
877 East March Lane, Stockton (4), CA  
Real Estate And Accumulated Depreciation  
Encumbrances 7,411us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMarchLane877StocktonCAMember
Initial Cost to Company  
Land 1,176us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMarchLane877StocktonCAMember
Buildings, Improvements & Equipment 11,171us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMarchLane877StocktonCAMember
Cost Capitalized Subsequent to Acquisition 5,498snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMarchLane877StocktonCAMember
Cost at the end of the period  
Land 1,176us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMarchLane877StocktonCAMember
Buildings, Improvements & Equipment 16,669us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMarchLane877StocktonCAMember
Total 17,845us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMarchLane877StocktonCAMember
Accumulated Depreciation 5,036us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMarchLane877StocktonCAMember
93 W Avenida de Los Arboles, Thousand Oaks, CA  
Initial Cost to Company  
Land 622us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WAvenidaDeLosArboles93ThousandOaksCAMember
Buildings, Improvements & Equipment 2,522us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WAvenidaDeLosArboles93ThousandOaksCAMember
Cost Capitalized Subsequent to Acquisition 2,468snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WAvenidaDeLosArboles93ThousandOaksCAMember
Cost at the end of the period  
Land 622us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WAvenidaDeLosArboles93ThousandOaksCAMember
Buildings, Improvements & Equipment 4,990us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WAvenidaDeLosArboles93ThousandOaksCAMember
Total 5,612us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WAvenidaDeLosArboles93ThousandOaksCAMember
Accumulated Depreciation 2,520us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WAvenidaDeLosArboles93ThousandOaksCAMember
6835 Hazeltine Street, Van Nuys, CA  
Initial Cost to Company  
Land 718us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HazeltineStreet6835VanNuysCAMember
Buildings, Improvements & Equipment 378us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HazeltineStreet6835VanNuysCAMember
Cost Capitalized Subsequent to Acquisition 785snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HazeltineStreet6835VanNuysCAMember
Cost at the end of the period  
Land 718us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HazeltineStreet6835VanNuysCAMember
Buildings, Improvements & Equipment 1,163us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HazeltineStreet6835VanNuysCAMember
Total 1,881us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HazeltineStreet6835VanNuysCAMember
Accumulated Depreciation 637us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HazeltineStreet6835VanNuysCAMember
1866 San Miguel Drive, Walnut Creek, CA  
Initial Cost to Company  
Land 2,010us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SanMiguelDrive1866WalnutCreekCAMember
Buildings, Improvements & Equipment 9,290us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SanMiguelDrive1866WalnutCreekCAMember
Cost Capitalized Subsequent to Acquisition 2,601snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SanMiguelDrive1866WalnutCreekCAMember
Cost at the end of the period  
Land 3,360us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SanMiguelDrive1866WalnutCreekCAMember
Buildings, Improvements & Equipment 10,541us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SanMiguelDrive1866WalnutCreekCAMember
Total 13,901us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SanMiguelDrive1866WalnutCreekCAMember
Accumulated Depreciation 870us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SanMiguelDrive1866WalnutCreekCAMember
515 Fairview, Canon City, CO  
Initial Cost to Company  
Land 292us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Fairview515CanonCityCOMember
Buildings, Improvements & Equipment 6,228us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Fairview515CanonCityCOMember
Cost Capitalized Subsequent to Acquisition 1,066snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Fairview515CanonCityCOMember
Impairment (3,512)snh_RealEstateAndAccumulatedDepreciationCarryingAmountOfImpairment
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Fairview515CanonCityCOMember
Cost at the end of the period  
Land 292us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Fairview515CanonCityCOMember
Buildings, Improvements & Equipment 3,782us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Fairview515CanonCityCOMember
Total 4,074us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Fairview515CanonCityCOMember
Accumulated Depreciation 1,561us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Fairview515CanonCityCOMember
110 West Van Buren, Colorado Springs, CO  
Initial Cost to Company  
Land 245us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestVanBuren110ColoradoSpringsCOMember
Buildings, Improvements & Equipment 5,236us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestVanBuren110ColoradoSpringsCOMember
Cost Capitalized Subsequent to Acquisition 1,687snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestVanBuren110ColoradoSpringsCOMember
Impairment (3,031)snh_RealEstateAndAccumulatedDepreciationCarryingAmountOfImpairment
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestVanBuren110ColoradoSpringsCOMember
Cost at the end of the period  
Land 245us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestVanBuren110ColoradoSpringsCOMember
Buildings, Improvements & Equipment 3,892us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestVanBuren110ColoradoSpringsCOMember
Total 4,137us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestVanBuren110ColoradoSpringsCOMember
Accumulated Depreciation 1,541us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestVanBuren110ColoradoSpringsCOMember
3920 East San Miguel Street, Colorado Springs, CO  
Initial Cost to Company  
Land 1,380us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastSanMiguelStreet3920ColoradoSpringsCOMember
Buildings, Improvements & Equipment 8,894us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastSanMiguelStreet3920ColoradoSpringsCOMember
Cost Capitalized Subsequent to Acquisition 279snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastSanMiguelStreet3920ColoradoSpringsCOMember
Cost at the end of the period  
Land 1,380us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastSanMiguelStreet3920ColoradoSpringsCOMember
Buildings, Improvements & Equipment 9,173us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastSanMiguelStreet3920ColoradoSpringsCOMember
Total 10,553us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastSanMiguelStreet3920ColoradoSpringsCOMember
Accumulated Depreciation 619us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastSanMiguelStreet3920ColoradoSpringsCOMember
2050 South Main, Delta, CO  
Initial Cost to Company  
Land 167us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthMain2050DeltaCOMember
Buildings, Improvements & Equipment 3,570us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthMain2050DeltaCOMember
Cost Capitalized Subsequent to Acquisition 763snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthMain2050DeltaCOMember
Cost at the end of the period  
Land 167us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthMain2050DeltaCOMember
Buildings, Improvements & Equipment 4,333us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthMain2050DeltaCOMember
Total 4,500us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthMain2050DeltaCOMember
Accumulated Depreciation 1,977us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthMain2050DeltaCOMember
2501 Little Bookcliff Drive, Grand Junction, CO  
Initial Cost to Company  
Land 204us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LittleBookcliffDrive2501GrandJunctionCOMember
Buildings, Improvements & Equipment 3,875us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LittleBookcliffDrive2501GrandJunctionCOMember
Cost Capitalized Subsequent to Acquisition 1,441snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LittleBookcliffDrive2501GrandJunctionCOMember
Cost at the end of the period  
Land 204us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LittleBookcliffDrive2501GrandJunctionCOMember
Buildings, Improvements & Equipment 5,316us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LittleBookcliffDrive2501GrandJunctionCOMember
Total 5,520us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LittleBookcliffDrive2501GrandJunctionCOMember
Accumulated Depreciation 2,853us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LittleBookcliffDrive2501GrandJunctionCOMember
2825 Patterson Road, Grand Junction, CO  
Initial Cost to Company  
Land 173us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PattersonRoad2825GrandJunctionCOMember
Buildings, Improvements & Equipment 2,583us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PattersonRoad2825GrandJunctionCOMember
Cost Capitalized Subsequent to Acquisition 2,124snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PattersonRoad2825GrandJunctionCOMember
Cost at the end of the period  
Land 173us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PattersonRoad2825GrandJunctionCOMember
Buildings, Improvements & Equipment 4,707us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PattersonRoad2825GrandJunctionCOMember
Total 4,880us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PattersonRoad2825GrandJunctionCOMember
Accumulated Depreciation 2,552us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PattersonRoad2825GrandJunctionCOMember
1599 Ingalls Street, Lakewood, CO  
Initial Cost to Company  
Land 232us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IngallsStreet1599LakewoodCOMember
Buildings, Improvements & Equipment 3,766us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IngallsStreet1599LakewoodCOMember
Cost Capitalized Subsequent to Acquisition 3,124snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IngallsStreet1599LakewoodCOMember
Cost at the end of the period  
Land 232us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IngallsStreet1599LakewoodCOMember
Buildings, Improvements & Equipment 6,890us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IngallsStreet1599LakewoodCOMember
Total 7,122us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IngallsStreet1599LakewoodCOMember
Accumulated Depreciation 3,542us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IngallsStreet1599LakewoodCOMember
5555 South Elati Street, Littleton, CO  
Initial Cost to Company  
Land 185us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthElatiStreet5555LittletonCOMember
Buildings, Improvements & Equipment 5,043us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthElatiStreet5555LittletonCOMember
Cost Capitalized Subsequent to Acquisition 2,368snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthElatiStreet5555LittletonCOMember
Cost at the end of the period  
Land 185us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthElatiStreet5555LittletonCOMember
Buildings, Improvements & Equipment 7,411us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthElatiStreet5555LittletonCOMember
Total 7,596us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthElatiStreet5555LittletonCOMember
Accumulated Depreciation 4,123us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthElatiStreet5555LittletonCOMember
8271 South Continental Divide Road, Littleton, CO  
Initial Cost to Company  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthContinentalDivideRoad8271LittletonCOMember
Buildings, Improvements & Equipment 3,507us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthContinentalDivideRoad8271LittletonCOMember
Cost at the end of the period  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthContinentalDivideRoad8271LittletonCOMember
Buildings, Improvements & Equipment 3,507us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthContinentalDivideRoad8271LittletonCOMember
Total 3,907us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthContinentalDivideRoad8271LittletonCOMember
Accumulated Depreciation 1,181us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthContinentalDivideRoad8271LittletonCOMember
9005 / 9025 Grant Street, Thornton, CO, Location 1  
Initial Cost to Company  
Land 961us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GrantStreet9005And9025ThorntonCOLocationOneMember
Buildings, Improvements & Equipment 10,867us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GrantStreet9005And9025ThorntonCOLocationOneMember
Cost Capitalized Subsequent to Acquisition 23snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GrantStreet9005And9025ThorntonCOLocationOneMember
Cost at the end of the period  
Land 982us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GrantStreet9005And9025ThorntonCOLocationOneMember
Buildings, Improvements & Equipment 10,869us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GrantStreet9005And9025ThorntonCOLocationOneMember
Total 11,851us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GrantStreet9005And9025ThorntonCOLocationOneMember
Accumulated Depreciation 544us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GrantStreet9005And9025ThorntonCOLocationOneMember
9005 / 9025 Grant Street, Thornton, CO, Location 2  
Initial Cost to Company  
Land 475us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GrantStreet9005And9025ThorntonCOLocationTwoMember
Buildings, Improvements & Equipment 909us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GrantStreet9005And9025ThorntonCOLocationTwoMember
Cost Capitalized Subsequent to Acquisition 123snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GrantStreet9005And9025ThorntonCOLocationTwoMember
Cost at the end of the period  
Land 475us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GrantStreet9005And9025ThorntonCOLocationTwoMember
Buildings, Improvements & Equipment 1,032us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GrantStreet9005And9025ThorntonCOLocationTwoMember
Total 1,507us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GrantStreet9005And9025ThorntonCOLocationTwoMember
Accumulated Depreciation 49us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GrantStreet9005And9025ThorntonCOLocationTwoMember
7809 W. 38th Avenue, Wheat Ridge, CO  
Initial Cost to Company  
Land 470us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_W38thAvenue7809WheatRidgeCOMember
Buildings, Improvements & Equipment 3,373us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_W38thAvenue7809WheatRidgeCOMember
Cost at the end of the period  
Land 470us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_W38thAvenue7809WheatRidgeCOMember
Buildings, Improvements & Equipment 3,373us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_W38thAvenue7809WheatRidgeCOMember
Total 3,843us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_W38thAvenue7809WheatRidgeCOMember
Accumulated Depreciation 401us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_W38thAvenue7809WheatRidgeCOMember
40 Sebethe Drive, Cromwell, CT  
Initial Cost to Company  
Land 570us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SebetheDrive40CromwellCTMember
Buildings, Improvements & Equipment 5,304us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SebetheDrive40CromwellCTMember
Cost Capitalized Subsequent to Acquisition 942snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SebetheDrive40CromwellCTMember
Cost at the end of the period  
Land 570us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SebetheDrive40CromwellCTMember
Buildings, Improvements & Equipment 6,246us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SebetheDrive40CromwellCTMember
Total 6,816us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SebetheDrive40CromwellCTMember
Accumulated Depreciation 611us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SebetheDrive40CromwellCTMember
866 North Main Street, Wallingford, CT  
Initial Cost to Company  
Land 430us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthMainStreet866WallingfordCTMember
Buildings, Improvements & Equipment 3,136us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthMainStreet866WallingfordCTMember
Cost Capitalized Subsequent to Acquisition 510snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthMainStreet866WallingfordCTMember
Cost at the end of the period  
Land 430us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthMainStreet866WallingfordCTMember
Buildings, Improvements & Equipment 3,646us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthMainStreet866WallingfordCTMember
Total 4,076us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthMainStreet866WallingfordCTMember
Accumulated Depreciation 376us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthMainStreet866WallingfordCTMember
1145 19th Street, Washington, DC  
Initial Cost to Company  
Land 13,600us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Street19th1145WashingtonDCMember
Buildings, Improvements & Equipment 24,880us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Street19th1145WashingtonDCMember
Cost Capitalized Subsequent to Acquisition 2,917snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Street19th1145WashingtonDCMember
Cost at the end of the period  
Land 13,600us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Street19th1145WashingtonDCMember
Buildings, Improvements & Equipment 27,797us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Street19th1145WashingtonDCMember
Total 41,397us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Street19th1145WashingtonDCMember
Accumulated Depreciation 3,927us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Street19th1145WashingtonDCMember
2141 K Street, Washington, DC  
Initial Cost to Company  
Land 13,700us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KStreet2141WashingtonDCMember
Buildings, Improvements & Equipment 8,400us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KStreet2141WashingtonDCMember
Cost Capitalized Subsequent to Acquisition 2,142snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KStreet2141WashingtonDCMember
Cost at the end of the period  
Land 13,700us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KStreet2141WashingtonDCMember
Buildings, Improvements & Equipment 10,542us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KStreet2141WashingtonDCMember
Total 24,242us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KStreet2141WashingtonDCMember
Accumulated Depreciation 1,460us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KStreet2141WashingtonDCMember
255 Possum Park Road, Newark, DE  
Initial Cost to Company  
Land 2,010us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PossumParkRoad255NewarkDEMember
Buildings, Improvements & Equipment 11,852us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PossumParkRoad255NewarkDEMember
Cost Capitalized Subsequent to Acquisition 2,893snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PossumParkRoad255NewarkDEMember
Cost at the end of the period  
Land 2,010us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PossumParkRoad255NewarkDEMember
Buildings, Improvements & Equipment 14,745us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PossumParkRoad255NewarkDEMember
Total 16,755us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PossumParkRoad255NewarkDEMember
Accumulated Depreciation 5,304us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PossumParkRoad255NewarkDEMember
4175 Ogletown Road / 501 South Harmony Road, Newark, DE  
Initial Cost to Company  
Land 1,500us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OgletownRoad4175AndSouthHarmonyRoad501NewarkDEMember
Buildings, Improvements & Equipment 19,447us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OgletownRoad4175AndSouthHarmonyRoad501NewarkDEMember
Cost Capitalized Subsequent to Acquisition 993snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OgletownRoad4175AndSouthHarmonyRoad501NewarkDEMember
Cost at the end of the period  
Land 1,500us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OgletownRoad4175AndSouthHarmonyRoad501NewarkDEMember
Buildings, Improvements & Equipment 20,440us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OgletownRoad4175AndSouthHarmonyRoad501NewarkDEMember
Total 21,940us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OgletownRoad4175AndSouthHarmonyRoad501NewarkDEMember
Accumulated Depreciation 3,410us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OgletownRoad4175AndSouthHarmonyRoad501NewarkDEMember
1212 Foulk Road, Wilmington (4), DE  
Real Estate And Accumulated Depreciation  
Encumbrances 7,202us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoulkRoad1212WilmingtonDEMember
Initial Cost to Company  
Land 1,179us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoulkRoad1212WilmingtonDEMember
Buildings, Improvements & Equipment 6,950us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoulkRoad1212WilmingtonDEMember
Cost Capitalized Subsequent to Acquisition 1,345snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoulkRoad1212WilmingtonDEMember
Cost at the end of the period  
Land 1,179us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoulkRoad1212WilmingtonDEMember
Buildings, Improvements & Equipment 8,295us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoulkRoad1212WilmingtonDEMember
Total 9,474us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoulkRoad1212WilmingtonDEMember
Accumulated Depreciation 3,294us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoulkRoad1212WilmingtonDEMember
1912 Marsh Road, Wilmington, DE  
Initial Cost to Company  
Land 4,365us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MarshRoad1912WilmingtonDEMember
Buildings, Improvements & Equipment 25,739us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MarshRoad1912WilmingtonDEMember
Cost Capitalized Subsequent to Acquisition 2,516snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MarshRoad1912WilmingtonDEMember
Cost at the end of the period  
Land 4,365us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MarshRoad1912WilmingtonDEMember
Buildings, Improvements & Equipment 28,255us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MarshRoad1912WilmingtonDEMember
Total 32,620us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MarshRoad1912WilmingtonDEMember
Accumulated Depreciation 10,186us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MarshRoad1912WilmingtonDEMember
2723 Shipley Road, Wilmington, DE  
Initial Cost to Company  
Land 869us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ShipleyRoad2723WilmingtonDEMember
Buildings, Improvements & Equipment 5,126us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ShipleyRoad2723WilmingtonDEMember
Cost Capitalized Subsequent to Acquisition 3,606snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ShipleyRoad2723WilmingtonDEMember
Cost at the end of the period  
Land 869us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ShipleyRoad2723WilmingtonDEMember
Buildings, Improvements & Equipment 8,732us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ShipleyRoad2723WilmingtonDEMember
Total 9,601us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ShipleyRoad2723WilmingtonDEMember
Accumulated Depreciation 3,203us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ShipleyRoad2723WilmingtonDEMember
407 Foulk Road, Wilmington, DE  
Initial Cost to Company  
Land 38us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoulkRoad407WilmingtonDEMember
Buildings, Improvements & Equipment 227us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoulkRoad407WilmingtonDEMember
Cost Capitalized Subsequent to Acquisition 1,216snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoulkRoad407WilmingtonDEMember
Cost at the end of the period  
Land 38us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoulkRoad407WilmingtonDEMember
Buildings, Improvements & Equipment 1,443us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoulkRoad407WilmingtonDEMember
Total 1,481us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoulkRoad407WilmingtonDEMember
Accumulated Depreciation 461us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoulkRoad407WilmingtonDEMember
13545 Progress Boulevard, Alachua, FL  
Initial Cost to Company  
Land 512us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13545AlachuaFLMember
Buildings, Improvements & Equipment 4,935us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13545AlachuaFLMember
Cost at the end of the period  
Land 512us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13545AlachuaFLMember
Buildings, Improvements & Equipment 4,935us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13545AlachuaFLMember
Total 5,447us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13545AlachuaFLMember
Accumulated Depreciation 442us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13545AlachuaFLMember
13631 Progress Boulevard, Alachua, FL  
Initial Cost to Company  
Land 512us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13631AlachuaFLMember
Buildings, Improvements & Equipment 4,941us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13631AlachuaFLMember
Cost at the end of the period  
Land 512us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13631AlachuaFLMember
Buildings, Improvements & Equipment 4,941us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13631AlachuaFLMember
Total 5,453us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13631AlachuaFLMember
Accumulated Depreciation 443us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13631AlachuaFLMember
13709 Progress Boulevard, Alachua, FL  
Initial Cost to Company  
Land 1,080us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13709AlachuaFLMember
Buildings, Improvements & Equipment 1,675us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13709AlachuaFLMember
Cost Capitalized Subsequent to Acquisition 203snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13709AlachuaFLMember
Cost at the end of the period  
Land 1,080us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13709AlachuaFLMember
Buildings, Improvements & Equipment 1,878us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13709AlachuaFLMember
Total 2,958us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13709AlachuaFLMember
Accumulated Depreciation 156us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13709AlachuaFLMember
13859 Progress Boulevard, Alachua (4), FL  
Real Estate And Accumulated Depreciation  
Encumbrances 3,348us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13859AlachuaFLMember
Initial Cost to Company  
Land 570us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13859AlachuaFLMember
Buildings, Improvements & Equipment 4,276us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13859AlachuaFLMember
Cost Capitalized Subsequent to Acquisition 4snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13859AlachuaFLMember
Cost at the end of the period  
Land 570us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13859AlachuaFLMember
Buildings, Improvements & Equipment 4,280us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13859AlachuaFLMember
Total 4,850us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13859AlachuaFLMember
Accumulated Depreciation 367us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressBoulevard13859AlachuaFLMember
Progress Center - Lot 1 Property, Alachua, FL  
Initial Cost to Company  
Land 165us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CenterLot1PropertyProgressAlachuaFLMember
Cost at the end of the period  
Land 165us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CenterLot1PropertyProgressAlachuaFLMember
Total 165us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CenterLot1PropertyProgressAlachuaFLMember
Progress Center - Lot 4 Property, Alachua, FL  
Initial Cost to Company  
Land 331us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CenterLot4PropertyProgressAlachuaFLMember
Cost at the end of the period  
Land 331us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CenterLot4PropertyProgressAlachuaFLMember
Total 331us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CenterLot4PropertyProgressAlachuaFLMember
Progress Vacant Land (47 acres), Alachua, FL  
Initial Cost to Company  
Land 4,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressVacantLand47AcresAlachuaFLMember
Cost at the end of the period  
Land 4,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressVacantLand47AcresAlachuaFLMember
Total 4,000us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProgressVacantLand47AcresAlachuaFLMember
22601 Camino Del Mar, Boca Raton (4), FL  
Initial Cost to Company  
Land 3,200us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CaminoDelMar22601BocaRatonFLMember
Buildings, Improvements & Equipment 46,800us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CaminoDelMar22601BocaRatonFLMember
Cost Capitalized Subsequent to Acquisition 1,777snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CaminoDelMar22601BocaRatonFLMember
Cost at the end of the period  
Land 3,200us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CaminoDelMar22601BocaRatonFLMember
Buildings, Improvements & Equipment 48,577us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CaminoDelMar22601BocaRatonFLMember
Total 51,777us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CaminoDelMar22601BocaRatonFLMember
Accumulated Depreciation 4,291us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CaminoDelMar22601BocaRatonFLMember
6343 Via de Sonrisa del Sur, Boca Raton, FL  
Initial Cost to Company  
Land 4,166us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ViaDeSonrisadelSur6343BocaRatonFLMember
Buildings, Improvements & Equipment 39,633us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ViaDeSonrisadelSur6343BocaRatonFLMember
Cost Capitalized Subsequent to Acquisition 729snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ViaDeSonrisadelSur6343BocaRatonFLMember
Cost at the end of the period  
Land 4,166us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ViaDeSonrisadelSur6343BocaRatonFLMember
Buildings, Improvements & Equipment 40,362us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ViaDeSonrisadelSur6343BocaRatonFLMember
Total 44,528us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ViaDeSonrisadelSur6343BocaRatonFLMember
Accumulated Depreciation 20,809us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ViaDeSonrisadelSur6343BocaRatonFLMember
1325 S. Congress Avenue, Boynton Beach, FL  
Initial Cost to Company  
Land 1,620us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SCongressAvenue1325BoyntonBeachFLMember
Buildings, Improvements & Equipment 5,341us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SCongressAvenue1325BoyntonBeachFLMember
Cost Capitalized Subsequent to Acquisition 33snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SCongressAvenue1325BoyntonBeachFLMember
Cost at the end of the period  
Land 1,620us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SCongressAvenue1325BoyntonBeachFLMember
Buildings, Improvements & Equipment 5,374us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SCongressAvenue1325BoyntonBeachFLMember
Total 6,994us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SCongressAvenue1325BoyntonBeachFLMember
Accumulated Depreciation 329us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SCongressAvenue1325BoyntonBeachFLMember
1425 Congress Avenue, Boynton Beach, FL  
Initial Cost to Company  
Land 2,390us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CongressAvenue1425BoyntonBeachFLMember
Buildings, Improvements & Equipment 14,768us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CongressAvenue1425BoyntonBeachFLMember
Cost Capitalized Subsequent to Acquisition 1,306snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CongressAvenue1425BoyntonBeachFLMember
Cost at the end of the period  
Land 2,390us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CongressAvenue1425BoyntonBeachFLMember
Buildings, Improvements & Equipment 16,074us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CongressAvenue1425BoyntonBeachFLMember
Total 18,464us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CongressAvenue1425BoyntonBeachFLMember
Accumulated Depreciation 1,509us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CongressAvenue1425BoyntonBeachFLMember
1416 Country Club Blvd., Cape Coral, FL  
Initial Cost to Company  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CountryClubBlvd1416CapeCoralFLMember
Buildings, Improvements & Equipment 2,907us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CountryClubBlvd1416CapeCoralFLMember
Cost at the end of the period  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CountryClubBlvd1416CapeCoralFLMember
Buildings, Improvements & Equipment 2,907us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CountryClubBlvd1416CapeCoralFLMember
Total 3,307us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CountryClubBlvd1416CapeCoralFLMember
Accumulated Depreciation 982us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CountryClubBlvd1416CapeCoralFLMember
8500 Royal Palm Boulevard, Coral Springs, FL  
Initial Cost to Company  
Land 3,410us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RoyalPalmBoulevard8500CoralSpringsFLMember
Buildings, Improvements & Equipment 20,104us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RoyalPalmBoulevard8500CoralSpringsFLMember
Cost Capitalized Subsequent to Acquisition 23,072snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RoyalPalmBoulevard8500CoralSpringsFLMember
Cost at the end of the period  
Land 3,410us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RoyalPalmBoulevard8500CoralSpringsFLMember
Buildings, Improvements & Equipment 43,176us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RoyalPalmBoulevard8500CoralSpringsFLMember
Total 46,586us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RoyalPalmBoulevard8500CoralSpringsFLMember
Accumulated Depreciation 11,402us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RoyalPalmBoulevard8500CoralSpringsFLMember
1208 South Military Trail, Deerfield Beach, FL  
Initial Cost to Company  
Land 1,690us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthMilitaryTrail1208DeerfieldBeachFLMember
Buildings, Improvements & Equipment 14,972us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthMilitaryTrail1208DeerfieldBeachFLMember
Cost Capitalized Subsequent to Acquisition 8,695snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthMilitaryTrail1208DeerfieldBeachFLMember
Cost at the end of the period  
Land 1,690us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthMilitaryTrail1208DeerfieldBeachFLMember
Buildings, Improvements & Equipment 23,667us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthMilitaryTrail1208DeerfieldBeachFLMember
Total 25,357us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthMilitaryTrail1208DeerfieldBeachFLMember
Accumulated Depreciation 8,587us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthMilitaryTrail1208DeerfieldBeachFLMember
3001 Deer Creek Boulevard, Deerfield Beach, FL  
Initial Cost to Company  
Land 3,196us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerCreekBoulevard3001DeerfieldBeachFLMember
Buildings, Improvements & Equipment 18,848us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerCreekBoulevard3001DeerfieldBeachFLMember
Cost Capitalized Subsequent to Acquisition 15,265snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerCreekBoulevard3001DeerfieldBeachFLMember
Cost at the end of the period  
Land 3,196us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerCreekBoulevard3001DeerfieldBeachFLMember
Buildings, Improvements & Equipment 34,113us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerCreekBoulevard3001DeerfieldBeachFLMember
Total 37,309us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerCreekBoulevard3001DeerfieldBeachFLMember
Accumulated Depreciation 10,016us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerCreekBoulevard3001DeerfieldBeachFLMember
12780 Kenwood Lane, Fort Myers, FL  
Initial Cost to Company  
Land 369us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KenwoodLane12780FortMyersFLMember
Buildings, Improvements & Equipment 2,174us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KenwoodLane12780FortMyersFLMember
Cost Capitalized Subsequent to Acquisition 2,368snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KenwoodLane12780FortMyersFLMember
Cost at the end of the period  
Land 369us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KenwoodLane12780FortMyersFLMember
Buildings, Improvements & Equipment 4,542us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KenwoodLane12780FortMyersFLMember
Total 4,911us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KenwoodLane12780FortMyersFLMember
Accumulated Depreciation 1,340us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KenwoodLane12780FortMyersFLMember
2525 East First Street, Fort Myers, FL  
Initial Cost to Company  
Land 2,385us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastFirstStreet2525FortMyersFLMember
Buildings, Improvements & Equipment 21,137us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastFirstStreet2525FortMyersFLMember
Cost Capitalized Subsequent to Acquisition 2,461snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastFirstStreet2525FortMyersFLMember
Cost at the end of the period  
Land 2,525us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastFirstStreet2525FortMyersFLMember
Buildings, Improvements & Equipment 23,458us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastFirstStreet2525FortMyersFLMember
Total 25,983us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastFirstStreet2525FortMyersFLMember
Accumulated Depreciation 11,304us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastFirstStreet2525FortMyersFLMember
1825 Ridgewood Avenue, Holly Hill (4), FL  
Real Estate And Accumulated Depreciation  
Encumbrances 12,184us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RidgewoodAvenue1825HollyHillFLMember
Initial Cost to Company  
Land 900us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RidgewoodAvenue1825HollyHillFLMember
Buildings, Improvements & Equipment 21,202us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RidgewoodAvenue1825HollyHillFLMember
Cost Capitalized Subsequent to Acquisition 1,343snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RidgewoodAvenue1825HollyHillFLMember
Cost at the end of the period  
Land 900us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RidgewoodAvenue1825HollyHillFLMember
Buildings, Improvements & Equipment 22,545us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RidgewoodAvenue1825HollyHillFLMember
Total 23,445us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RidgewoodAvenue1825HollyHillFLMember
Accumulated Depreciation 2,190us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RidgewoodAvenue1825HollyHillFLMember
2480 North Park Road, Hollywood, FL  
Initial Cost to Company  
Land 4,500us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthParkRoad2480HollywoodFLMember
Buildings, Improvements & Equipment 40,500us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthParkRoad2480HollywoodFLMember
Cost Capitalized Subsequent to Acquisition 10,355snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthParkRoad2480HollywoodFLMember
Cost at the end of the period  
Land 4,500us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthParkRoad2480HollywoodFLMember
Buildings, Improvements & Equipment 50,855us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthParkRoad2480HollywoodFLMember
Total 55,355us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthParkRoad2480HollywoodFLMember
Accumulated Depreciation 4,010us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthParkRoad2480HollywoodFLMember
8901 Tamiami Trail E., Naples, FL  
Initial Cost to Company  
Land 3,200us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TamiamiTrailE8901NaplesFLMember
Buildings, Improvements & Equipment 2,898us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TamiamiTrailE8901NaplesFLMember
Cost Capitalized Subsequent to Acquisition 12,403snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TamiamiTrailE8901NaplesFLMember
Cost at the end of the period  
Land 3,200us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TamiamiTrailE8901NaplesFLMember
Buildings, Improvements & Equipment 15,301us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TamiamiTrailE8901NaplesFLMember
Total 18,501us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TamiamiTrailE8901NaplesFLMember
Accumulated Depreciation 3,048us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TamiamiTrailE8901NaplesFLMember
12780 Waterford Lakes Parkway, Orlando, FL  
Initial Cost to Company  
Land 977us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaterfordLakesParkway12780OrlandoFLMember
Buildings, Improvements & Equipment 3,926us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaterfordLakesParkway12780OrlandoFLMember
Cost at the end of the period  
Land 977us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaterfordLakesParkway12780OrlandoFLMember
Buildings, Improvements & Equipment 3,926us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaterfordLakesParkway12780OrlandoFLMember
Total 4,903us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaterfordLakesParkway12780OrlandoFLMember
Accumulated Depreciation 98us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaterfordLakesParkway12780OrlandoFLMember
1603 S. Hiawassee Road, Orlando, FL  
Initial Cost to Company  
Land 488us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SHiawasseeRoad1603OrlandoFLMember
Buildings, Improvements & Equipment 2,617us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SHiawasseeRoad1603OrlandoFLMember
Cost at the end of the period  
Land 488us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SHiawasseeRoad1603OrlandoFLMember
Buildings, Improvements & Equipment 2,617us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SHiawasseeRoad1603OrlandoFLMember
Total 3,105us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SHiawasseeRoad1603OrlandoFLMember
Accumulated Depreciation 65us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SHiawasseeRoad1603OrlandoFLMember
1825 N. Mills Avenue, Orlando, Orlando, FL  
Initial Cost to Company  
Land 519us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1825OrlandoFLMember
Buildings, Improvements & Equipment 1,799us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1825OrlandoFLMember
Cost Capitalized Subsequent to Acquisition 342snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1825OrlandoFLMember
Cost at the end of the period  
Land 519us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1825OrlandoFLMember
Buildings, Improvements & Equipment 2,141us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1825OrlandoFLMember
Total 2,660us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1825OrlandoFLMember
Accumulated Depreciation 309us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1825OrlandoFLMember
1911 N. Mills Avenue, Orlando, Orlando, FL  
Initial Cost to Company  
Land 1,946us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1911OrlandoFLMember
Buildings, Improvements & Equipment 7,197us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1911OrlandoFLMember
Cost Capitalized Subsequent to Acquisition 658snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1911OrlandoFLMember
Cost at the end of the period  
Land 1,946us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1911OrlandoFLMember
Buildings, Improvements & Equipment 7,855us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1911OrlandoFLMember
Total 9,801us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1911OrlandoFLMember
Accumulated Depreciation 1,176us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1911OrlandoFLMember
1925 N. Mills Avenue, Orlando, Orlando, FL  
Initial Cost to Company  
Land 135us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1925OrlandoFLMember
Buildings, Improvements & Equipment 532us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1925OrlandoFLMember
Cost Capitalized Subsequent to Acquisition 49snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1925OrlandoFLMember
Cost at the end of the period  
Land 135us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1925OrlandoFLMember
Buildings, Improvements & Equipment 581us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1925OrlandoFLMember
Total 716us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1925OrlandoFLMember
Accumulated Depreciation 83us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NMillsAvenueOrlando1925OrlandoFLMember
250 N. Alafaya Trail, Orlando, FL  
Initial Cost to Company  
Land 967us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NAlafayaTrail250OrlandoFLMember
Buildings, Improvements & Equipment 4,362us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NAlafayaTrail250OrlandoFLMember
Cost at the end of the period  
Land 967us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NAlafayaTrail250OrlandoFLMember
Buildings, Improvements & Equipment 4,362us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NAlafayaTrail250OrlandoFLMember
Total 5,329us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NAlafayaTrail250OrlandoFLMember
Accumulated Depreciation 109us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NAlafayaTrail250OrlandoFLMember
45 Katherine Boulevard, Palm Harbor, FL  
Initial Cost to Company  
Land 3,379us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KatherineBoulevard45PalmHarborFLMember
Buildings, Improvements & Equipment 29,945us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KatherineBoulevard45PalmHarborFLMember
Cost Capitalized Subsequent to Acquisition 1,891snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KatherineBoulevard45PalmHarborFLMember
Cost at the end of the period  
Land 3,379us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KatherineBoulevard45PalmHarborFLMember
Buildings, Improvements & Equipment 31,836us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KatherineBoulevard45PalmHarborFLMember
Total 35,215us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KatherineBoulevard45PalmHarborFLMember
Accumulated Depreciation 15,953us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KatherineBoulevard45PalmHarborFLMember
900 West Lake Road, Palm Harbor (4), FL  
Real Estate And Accumulated Depreciation  
Encumbrances 23,032us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestLakeRoad900PalmHarborFLMember
Initial Cost to Company  
Land 3,449us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestLakeRoad900PalmHarborFLMember
Buildings, Improvements & Equipment 20,336us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestLakeRoad900PalmHarborFLMember
Cost Capitalized Subsequent to Acquisition 6,217snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestLakeRoad900PalmHarborFLMember
Cost at the end of the period  
Land 3,449us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestLakeRoad900PalmHarborFLMember
Buildings, Improvements & Equipment 26,553us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestLakeRoad900PalmHarborFLMember
Total 30,002us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestLakeRoad900PalmHarborFLMember
Accumulated Depreciation 9,271us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestLakeRoad900PalmHarborFLMember
8500 West Sunrise Boulevard, Plantation (4), FL  
Initial Cost to Company  
Land 4,700us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSunriseBoulevard8500PlantationFLMember
Buildings, Improvements & Equipment 24,300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSunriseBoulevard8500PlantationFLMember
Cost Capitalized Subsequent to Acquisition 2,224snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSunriseBoulevard8500PlantationFLMember
Cost at the end of the period  
Land 4,700us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSunriseBoulevard8500PlantationFLMember
Buildings, Improvements & Equipment 26,524us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSunriseBoulevard8500PlantationFLMember
Total 31,224us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSunriseBoulevard8500PlantationFLMember
Accumulated Depreciation 2,739us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSunriseBoulevard8500PlantationFLMember
1371 South Ocean Boulevard, Pompano Beach, FL  
Initial Cost to Company  
Land 2,500us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthOceanBoulevard1371PompanoBeachFLMember
Buildings, Improvements & Equipment 15,500us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthOceanBoulevard1371PompanoBeachFLMember
Cost Capitalized Subsequent to Acquisition 1,815snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthOceanBoulevard1371PompanoBeachFLMember
Cost at the end of the period  
Land 2,500us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthOceanBoulevard1371PompanoBeachFLMember
Buildings, Improvements & Equipment 17,315us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthOceanBoulevard1371PompanoBeachFLMember
Total 19,815us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthOceanBoulevard1371PompanoBeachFLMember
Accumulated Depreciation 1,752us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthOceanBoulevard1371PompanoBeachFLMember
2701 North Course Dr., Pompano Beach, FL  
Initial Cost to Company  
Land 7,700us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthCourseDr2701PompanoBeachFLMember
Buildings, Improvements & Equipment 2,127us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthCourseDr2701PompanoBeachFLMember
Cost Capitalized Subsequent to Acquisition 34,558snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthCourseDr2701PompanoBeachFLMember
Cost at the end of the period  
Land 7,700us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthCourseDr2701PompanoBeachFLMember
Buildings, Improvements & Equipment 36,685us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthCourseDr2701PompanoBeachFLMember
Total 44,385us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthCourseDr2701PompanoBeachFLMember
Accumulated Depreciation 7,562us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthCourseDr2701PompanoBeachFLMember
20480 Veterans Boulevard, Port Charlotte, FL  
Initial Cost to Company  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VeteransBoulevard20480PortCharlotteFLMember
Buildings, Improvements & Equipment 11,934us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VeteransBoulevard20480PortCharlotteFLMember
Cost Capitalized Subsequent to Acquisition 902snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VeteransBoulevard20480PortCharlotteFLMember
Cost at the end of the period  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VeteransBoulevard20480PortCharlotteFLMember
Buildings, Improvements & Equipment 12,836us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VeteransBoulevard20480PortCharlotteFLMember
Total 13,236us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VeteransBoulevard20480PortCharlotteFLMember
Accumulated Depreciation 1,277us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VeteransBoulevard20480PortCharlotteFLMember
1699 S.E. Lyngate Drive, Port St. Lucie, FL  
Initial Cost to Company  
Land 1,242us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SELyngateDrive1699PortStLucieFLMember
Buildings, Improvements & Equipment 11,009us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SELyngateDrive1699PortStLucieFLMember
Cost Capitalized Subsequent to Acquisition 729snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SELyngateDrive1699PortStLucieFLMember
Cost at the end of the period  
Land 1,242us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SELyngateDrive1699PortStLucieFLMember
Buildings, Improvements & Equipment 11,738us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SELyngateDrive1699PortStLucieFLMember
Total 12,980us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SELyngateDrive1699PortStLucieFLMember
Accumulated Depreciation 5,864us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SELyngateDrive1699PortStLucieFLMember
501 N.W. Cashmere Boulevard, Port St. Lucie, FL  
Initial Cost to Company  
Land 890us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NWCashmereBoulevard501PortStLucieFLMember
Buildings, Improvements & Equipment 9,345us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NWCashmereBoulevard501PortStLucieFLMember
Cost Capitalized Subsequent to Acquisition 494snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NWCashmereBoulevard501PortStLucieFLMember
Cost at the end of the period  
Land 890us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NWCashmereBoulevard501PortStLucieFLMember
Buildings, Improvements & Equipment 9,839us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NWCashmereBoulevard501PortStLucieFLMember
Total 10,729us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NWCashmereBoulevard501PortStLucieFLMember
Accumulated Depreciation 982us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NWCashmereBoulevard501PortStLucieFLMember
900 South Harbour Island Blvd., Tampa, FL  
Initial Cost to Company  
Land 4,850us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthHarbourIslandBlvd900TampaFLMember
Buildings, Improvements & Equipment 6,349us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthHarbourIslandBlvd900TampaFLMember
Cost Capitalized Subsequent to Acquisition 7snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthHarbourIslandBlvd900TampaFLMember
Cost at the end of the period  
Land 4,850us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthHarbourIslandBlvd900TampaFLMember
Buildings, Improvements & Equipment 6,356us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthHarbourIslandBlvd900TampaFLMember
Total 11,206us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthHarbourIslandBlvd900TampaFLMember
Accumulated Depreciation 1,145us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthHarbourIslandBlvd900TampaFLMember
111 Executive Center Drive, West Palm Beach, FL  
Initial Cost to Company  
Land 2,061us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveCenterDrive111WestPalmBeachFLMember
Buildings, Improvements & Equipment 12,153us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveCenterDrive111WestPalmBeachFLMember
Cost Capitalized Subsequent to Acquisition 9,383snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveCenterDrive111WestPalmBeachFLMember
Cost at the end of the period  
Land 2,061us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveCenterDrive111WestPalmBeachFLMember
Buildings, Improvements & Equipment 21,536us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveCenterDrive111WestPalmBeachFLMember
Total 23,597us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveCenterDrive111WestPalmBeachFLMember
Accumulated Depreciation 7,051us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveCenterDrive111WestPalmBeachFLMember
855 North Point Pkwy, Alpharetta, GA  
Initial Cost to Company  
Land 5,390us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthPointPkwy855AlpharettaGAMember
Buildings, Improvements & Equipment 26,712us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthPointPkwy855AlpharettaGAMember
Cost at the end of the period  
Land 5,390us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthPointPkwy855AlpharettaGAMember
Buildings, Improvements & Equipment 26,712us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthPointPkwy855AlpharettaGAMember
Total 32,102us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthPointPkwy855AlpharettaGAMember
Accumulated Depreciation 4,257us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthPointPkwy855AlpharettaGAMember
1291 Cedar Shoals Drive, Athens, GA  
Initial Cost to Company  
Land 337us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CedarShoalsDrive1291AthensGAMember
Buildings, Improvements & Equipment 4,006us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CedarShoalsDrive1291AthensGAMember
Cost Capitalized Subsequent to Acquisition 407snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CedarShoalsDrive1291AthensGAMember
Cost at the end of the period  
Land 337us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CedarShoalsDrive1291AthensGAMember
Buildings, Improvements & Equipment 4,413us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CedarShoalsDrive1291AthensGAMember
Total 4,750us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CedarShoalsDrive1291AthensGAMember
Accumulated Depreciation 1,231us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CedarShoalsDrive1291AthensGAMember
1515 Sheridan Road, Atlanta, GA  
Initial Cost to Company  
Land 5,800us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SheridanRoad1515AtlantaGAMember
Buildings, Improvements & Equipment 9,305us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SheridanRoad1515AtlantaGAMember
Cost Capitalized Subsequent to Acquisition 3snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SheridanRoad1515AtlantaGAMember
Cost at the end of the period  
Land 5,800us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SheridanRoad1515AtlantaGAMember
Buildings, Improvements & Equipment 9,308us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SheridanRoad1515AtlantaGAMember
Total 15,108us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SheridanRoad1515AtlantaGAMember
Accumulated Depreciation 1,658us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SheridanRoad1515AtlantaGAMember
59 Executive Park South, Atlanta, GA  
Initial Cost to Company  
Land 4,980us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveParkSouth59AtlantaGAMember
Buildings, Improvements & Equipment 11,266us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveParkSouth59AtlantaGAMember
Cost Capitalized Subsequent to Acquisition 586snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveParkSouth59AtlantaGAMember
Cost at the end of the period  
Land 4,980us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveParkSouth59AtlantaGAMember
Buildings, Improvements & Equipment 11,852us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveParkSouth59AtlantaGAMember
Total 16,832us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveParkSouth59AtlantaGAMember
Accumulated Depreciation 1,187us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveParkSouth59AtlantaGAMember
240 Marietta Highway, Canton, GA  
Initial Cost to Company  
Land 806us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MariettaHighway240CantonGAMember
Buildings, Improvements & Equipment 8,555us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MariettaHighway240CantonGAMember
Cost Capitalized Subsequent to Acquisition 620snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MariettaHighway240CantonGAMember
Cost at the end of the period  
Land 806us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MariettaHighway240CantonGAMember
Buildings, Improvements & Equipment 9,175us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MariettaHighway240CantonGAMember
Total 9,981us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MariettaHighway240CantonGAMember
Accumulated Depreciation 321us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MariettaHighway240CantonGAMember
4500 South Stadium Drive, Columbus, GA  
Initial Cost to Company  
Land 294us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthStadiumDrive4500ColumbusGAMember
Buildings, Improvements & Equipment 3,505us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthStadiumDrive4500ColumbusGAMember
Cost Capitalized Subsequent to Acquisition 143snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthStadiumDrive4500ColumbusGAMember
Cost at the end of the period  
Land 294us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthStadiumDrive4500ColumbusGAMember
Buildings, Improvements & Equipment 3,648us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthStadiumDrive4500ColumbusGAMember
Total 3,942us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthStadiumDrive4500ColumbusGAMember
Accumulated Depreciation 1,032us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthStadiumDrive4500ColumbusGAMember
1352 Wellbrook Circle, Conyers, GA  
Initial Cost to Company  
Land 342us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WellbrookCircle1352ConyersGAMember
Buildings, Improvements & Equipment 4,068us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WellbrookCircle1352ConyersGAMember
Cost Capitalized Subsequent to Acquisition 823snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WellbrookCircle1352ConyersGAMember
Cost at the end of the period  
Land 342us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WellbrookCircle1352ConyersGAMember
Buildings, Improvements & Equipment 4,891us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WellbrookCircle1352ConyersGAMember
Total 5,233us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WellbrookCircle1352ConyersGAMember
Accumulated Depreciation 1,299us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WellbrookCircle1352ConyersGAMember
1501 Milstead Road, Conyers, GA  
Initial Cost to Company  
Land 750us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MilsteadRoad1501ConyersGAMember
Buildings, Improvements & Equipment 7,788us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MilsteadRoad1501ConyersGAMember
Cost at the end of the period  
Land 750us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MilsteadRoad1501ConyersGAMember
Buildings, Improvements & Equipment 7,788us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MilsteadRoad1501ConyersGAMember
Total 8,538us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MilsteadRoad1501ConyersGAMember
Accumulated Depreciation 830us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MilsteadRoad1501ConyersGAMember
4960 Jot Em Down Road, Cumming, GA  
Initial Cost to Company  
Land 1,548us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_JotEmDownRoad4960CummingGAMember
Buildings, Improvements & Equipment 18,666us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_JotEmDownRoad4960CummingGAMember
Cost Capitalized Subsequent to Acquisition 1,144snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_JotEmDownRoad4960CummingGAMember
Cost at the end of the period  
Land 1,548us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_JotEmDownRoad4960CummingGAMember
Buildings, Improvements & Equipment 19,810us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_JotEmDownRoad4960CummingGAMember
Total 21,358us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_JotEmDownRoad4960CummingGAMember
Accumulated Depreciation 759us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_JotEmDownRoad4960CummingGAMember
2470 Dug Gap Road, Dalton, GA  
Initial Cost to Company  
Land 262us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DugGapRoad2470DaltonGAMember
Buildings, Improvements & Equipment 3,119us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DugGapRoad2470DaltonGAMember
Cost Capitalized Subsequent to Acquisition 358snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DugGapRoad2470DaltonGAMember
Cost at the end of the period  
Land 262us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DugGapRoad2470DaltonGAMember
Buildings, Improvements & Equipment 3,477us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DugGapRoad2470DaltonGAMember
Total 3,739us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DugGapRoad2470DaltonGAMember
Accumulated Depreciation 941us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DugGapRoad2470DaltonGAMember
101 West Ponce De Leon Avenue, Decatur, GA  
Initial Cost to Company  
Land 3,500us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestPonceDeLeonAvenue101DecaturGAMember
Buildings, Improvements & Equipment 13,179us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestPonceDeLeonAvenue101DecaturGAMember
Cost at the end of the period  
Land 3,500us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestPonceDeLeonAvenue101DecaturGAMember
Buildings, Improvements & Equipment 13,179us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestPonceDeLeonAvenue101DecaturGAMember
Total 16,679us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestPonceDeLeonAvenue101DecaturGAMember
Accumulated Depreciation 851us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestPonceDeLeonAvenue101DecaturGAMember
2801 N. Decatur Road, Decatur, GA  
Initial Cost to Company  
Land 3,100us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NDecaturRoad2801DecaturGAMember
Buildings, Improvements & Equipment 4,436us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NDecaturRoad2801DecaturGAMember
Cost Capitalized Subsequent to Acquisition 515snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NDecaturRoad2801DecaturGAMember
Cost at the end of the period  
Land 3,100us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NDecaturRoad2801DecaturGAMember
Buildings, Improvements & Equipment 4,951us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NDecaturRoad2801DecaturGAMember
Total 8,051us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NDecaturRoad2801DecaturGAMember
Accumulated Depreciation 901us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NDecaturRoad2801DecaturGAMember
114 Penland Street, Ellijay, GA  
Initial Cost to Company  
Land 496us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PenlandStreet114EllijayGAMember
Buildings, Improvements & Equipment 7,107us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PenlandStreet114EllijayGAMember
Cost Capitalized Subsequent to Acquisition 344snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PenlandStreet114EllijayGAMember
Cost at the end of the period  
Land 496us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PenlandStreet114EllijayGAMember
Buildings, Improvements & Equipment 7,451us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PenlandStreet114EllijayGAMember
Total 7,947us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PenlandStreet114EllijayGAMember
Accumulated Depreciation 253us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PenlandStreet114EllijayGAMember
353 North Belair Road, Evans, GA  
Initial Cost to Company  
Land 230us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthBelairRoad353EvansGAMember
Buildings, Improvements & Equipment 2,663us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthBelairRoad353EvansGAMember
Cost Capitalized Subsequent to Acquisition 489snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthBelairRoad353EvansGAMember
Cost at the end of the period  
Land 230us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthBelairRoad353EvansGAMember
Buildings, Improvements & Equipment 3,152us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthBelairRoad353EvansGAMember
Total 3,382us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthBelairRoad353EvansGAMember
Accumulated Depreciation 869us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthBelairRoad353EvansGAMember
2435 Limestone Parkway, Gainesville, GA  
Initial Cost to Company  
Land 268us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LimestoneParkway2435GainesvilleGAMember
Buildings, Improvements & Equipment 3,186us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LimestoneParkway2435GainesvilleGAMember
Cost Capitalized Subsequent to Acquisition 193snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LimestoneParkway2435GainesvilleGAMember
Cost at the end of the period  
Land 268us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LimestoneParkway2435GainesvilleGAMember
Buildings, Improvements & Equipment 3,379us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LimestoneParkway2435GainesvilleGAMember
Total 3,647us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LimestoneParkway2435GainesvilleGAMember
Accumulated Depreciation 964us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LimestoneParkway2435GainesvilleGAMember
8080 Summit Business Parkway, Jonesboro, GA  
Initial Cost to Company  
Land 1,800us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SummitBusinessParkway8080JonesboroGAMember
Buildings, Improvements & Equipment 20,664us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SummitBusinessParkway8080JonesboroGAMember
Cost Capitalized Subsequent to Acquisition 525snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SummitBusinessParkway8080JonesboroGAMember
Cost at the end of the period  
Land 1,800us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SummitBusinessParkway8080JonesboroGAMember
Buildings, Improvements & Equipment 21,189us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SummitBusinessParkway8080JonesboroGAMember
Total 22,989us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SummitBusinessParkway8080JonesboroGAMember
Accumulated Depreciation 2,157us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SummitBusinessParkway8080JonesboroGAMember
6191 Peake Road, Macon, GA  
Initial Cost to Company  
Land 183us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PeakeRoad6191MaconGAMember
Buildings, Improvements & Equipment 2,179us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PeakeRoad6191MaconGAMember
Cost Capitalized Subsequent to Acquisition 285snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PeakeRoad6191MaconGAMember
Cost at the end of the period  
Land 183us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PeakeRoad6191MaconGAMember
Buildings, Improvements & Equipment 2,464us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PeakeRoad6191MaconGAMember
Total 2,647us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PeakeRoad6191MaconGAMember
Accumulated Depreciation 703us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PeakeRoad6191MaconGAMember
1360 Upper Hembree Road, Roswell, GA  
Initial Cost to Company  
Land 1,080us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UpperHembreeRoad1360RoswellGAMember
Buildings, Improvements & Equipment 6,138us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UpperHembreeRoad1360RoswellGAMember
Cost at the end of the period  
Land 1,080us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UpperHembreeRoad1360RoswellGAMember
Buildings, Improvements & Equipment 6,138us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UpperHembreeRoad1360RoswellGAMember
Total 7,218us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UpperHembreeRoad1360RoswellGAMember
Accumulated Depreciation 409us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UpperHembreeRoad1360RoswellGAMember
1 Savannah Square Drive, Savannah, GA  
Initial Cost to Company  
Land 1,200us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SavannahSquareDrive1SavannahGAMember
Buildings, Improvements & Equipment 19,090us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SavannahSquareDrive1SavannahGAMember
Cost Capitalized Subsequent to Acquisition 4,087snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SavannahSquareDrive1SavannahGAMember
Cost at the end of the period  
Land 1,200us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SavannahSquareDrive1SavannahGAMember
Buildings, Improvements & Equipment 23,177us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SavannahSquareDrive1SavannahGAMember
Total 24,377us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SavannahSquareDrive1SavannahGAMember
Accumulated Depreciation 4,907us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SavannahSquareDrive1SavannahGAMember
5200 Habersham Street, Savannah (4), GA  
Real Estate And Accumulated Depreciation  
Encumbrances 4,403us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HabershamStreet5200SavannahGAMember
Initial Cost to Company  
Land 800us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HabershamStreet5200SavannahGAMember
Buildings, Improvements & Equipment 7,800us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HabershamStreet5200SavannahGAMember
Cost Capitalized Subsequent to Acquisition 436snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HabershamStreet5200SavannahGAMember
Cost at the end of the period  
Land 800us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HabershamStreet5200SavannahGAMember
Buildings, Improvements & Equipment 8,236us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HabershamStreet5200SavannahGAMember
Total 9,036us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HabershamStreet5200SavannahGAMember
Accumulated Depreciation 826us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HabershamStreet5200SavannahGAMember
7410 Skidaway Road, Savannah, GA  
Initial Cost to Company  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SkidawayRoad7410SavannahGAMember
Buildings, Improvements & Equipment 5,670us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SkidawayRoad7410SavannahGAMember
Cost Capitalized Subsequent to Acquisition 795snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SkidawayRoad7410SavannahGAMember
Cost at the end of the period  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SkidawayRoad7410SavannahGAMember
Buildings, Improvements & Equipment 6,465us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SkidawayRoad7410SavannahGAMember
Total 6,865us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SkidawayRoad7410SavannahGAMember
Accumulated Depreciation 1,550us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SkidawayRoad7410SavannahGAMember
2078 Scenic Highway North, Snellville, GA  
Initial Cost to Company  
Land 870us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ScenicHighwayNorth2078SnellvilleGAMember
Buildings, Improvements & Equipment 4,030us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ScenicHighwayNorth2078SnellvilleGAMember
Cost Capitalized Subsequent to Acquisition 139snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ScenicHighwayNorth2078SnellvilleGAMember
Cost at the end of the period  
Land 870us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ScenicHighwayNorth2078SnellvilleGAMember
Buildings, Improvements & Equipment 4,169us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ScenicHighwayNorth2078SnellvilleGAMember
Total 5,039us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ScenicHighwayNorth2078SnellvilleGAMember
Accumulated Depreciation 593us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ScenicHighwayNorth2078SnellvilleGAMember
1300 Montreal Road, Tucker, GA  
Initial Cost to Company  
Land 690us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MontrealRoad1300TuckerGAMember
Buildings, Improvements & Equipment 6,210us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MontrealRoad1300TuckerGAMember
Cost Capitalized Subsequent to Acquisition 711snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MontrealRoad1300TuckerGAMember
Cost at the end of the period  
Land 690us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MontrealRoad1300TuckerGAMember
Buildings, Improvements & Equipment 6,921us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MontrealRoad1300TuckerGAMember
Total 7,611us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MontrealRoad1300TuckerGAMember
Accumulated Depreciation 1,842us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MontrealRoad1300TuckerGAMember
1100 Ward Avenue, Honolulu (4), HI  
Real Estate And Accumulated Depreciation  
Encumbrances 52,000us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WardAvenue1100HonoluluHIMember
Initial Cost to Company  
Land 11,200us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WardAvenue1100HonoluluHIMember
Buildings, Improvements & Equipment 55,618us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WardAvenue1100HonoluluHIMember
Cost Capitalized Subsequent to Acquisition 858snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WardAvenue1100HonoluluHIMember
Cost at the end of the period  
Land 11,200us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WardAvenue1100HonoluluHIMember
Buildings, Improvements & Equipment 56,476us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WardAvenue1100HonoluluHIMember
Total 67,676us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WardAvenue1100HonoluluHIMember
Accumulated Depreciation 3,501us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WardAvenue1100HonoluluHIMember
600 Manor Drive, Clarinda, IA  
Initial Cost to Company  
Land 77us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ManorDrive600ClarindaIAMember
Buildings, Improvements & Equipment 1,453us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ManorDrive600ClarindaIAMember
Cost Capitalized Subsequent to Acquisition 906snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ManorDrive600ClarindaIAMember
Cost at the end of the period  
Land 77us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ManorDrive600ClarindaIAMember
Buildings, Improvements & Equipment 2,359us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ManorDrive600ClarindaIAMember
Total 2,436us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ManorDrive600ClarindaIAMember
Accumulated Depreciation 1,365us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ManorDrive600ClarindaIAMember
2401 E. 8th Street, Des Moines, IA  
Initial Cost to Company  
Land 123us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_E8thStreet2401DesMoinesIAMember
Buildings, Improvements & Equipment 627us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_E8thStreet2401DesMoinesIAMember
Cost Capitalized Subsequent to Acquisition 1,307snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_E8thStreet2401DesMoinesIAMember
Cost at the end of the period  
Land 123us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_E8thStreet2401DesMoinesIAMember
Buildings, Improvements & Equipment 1,934us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_E8thStreet2401DesMoinesIAMember
Total 2,057us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_E8thStreet2401DesMoinesIAMember
Accumulated Depreciation 695us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_E8thStreet2401DesMoinesIAMember
608 Prairie Street, Mediapolis, IA  
Initial Cost to Company  
Land 94us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PrairieStreet608MediapolisIAMember
Buildings, Improvements & Equipment 1,776us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PrairieStreet608MediapolisIAMember
Cost Capitalized Subsequent to Acquisition 714snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PrairieStreet608MediapolisIAMember
Cost at the end of the period  
Land 94us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PrairieStreet608MediapolisIAMember
Buildings, Improvements & Equipment 2,490us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PrairieStreet608MediapolisIAMember
Total 2,584us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PrairieStreet608MediapolisIAMember
Accumulated Depreciation 1,456us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PrairieStreet608MediapolisIAMember
1015 West Summit, Winterset, IA  
Initial Cost to Company  
Land 111us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSummit1015WintersetIAMember
Buildings, Improvements & Equipment 2,099us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSummit1015WintersetIAMember
Cost Capitalized Subsequent to Acquisition 1,320snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSummit1015WintersetIAMember
Impairment (314)snh_RealEstateAndAccumulatedDepreciationCarryingAmountOfImpairment
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSummit1015WintersetIAMember
Cost at the end of the period  
Land 111us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSummit1015WintersetIAMember
Buildings, Improvements & Equipment 3,105us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSummit1015WintersetIAMember
Total 3,216us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSummit1015WintersetIAMember
Accumulated Depreciation 1,793us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSummit1015WintersetIAMember
2340 West Seltice Way, Coeur d'Alene, ID  
Initial Cost to Company  
Land 910us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSelticeWay2340CoeurdAleneIDMember
Buildings, Improvements & Equipment 7,170us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSelticeWay2340CoeurdAleneIDMember
Cost Capitalized Subsequent to Acquisition 259snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSelticeWay2340CoeurdAleneIDMember
Cost at the end of the period  
Land 910us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSelticeWay2340CoeurdAleneIDMember
Buildings, Improvements & Equipment 7,429us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSelticeWay2340CoeurdAleneIDMember
Total 8,339us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSelticeWay2340CoeurdAleneIDMember
Accumulated Depreciation 500us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSelticeWay2340CoeurdAleneIDMember
850 Lincoln Drive, Idaho Falls, ID  
Initial Cost to Company  
Land 510us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LincolnDrive850IdahoFallsIDMember
Buildings, Improvements & Equipment 6,640us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LincolnDrive850IdahoFallsIDMember
Cost Capitalized Subsequent to Acquisition 794snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LincolnDrive850IdahoFallsIDMember
Cost at the end of the period  
Land 510us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LincolnDrive850IdahoFallsIDMember
Buildings, Improvements & Equipment 7,434us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LincolnDrive850IdahoFallsIDMember
Total 7,944us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LincolnDrive850IdahoFallsIDMember
Accumulated Depreciation 480us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LincolnDrive850IdahoFallsIDMember
1250 West Central Road, Arlington Heights, IL  
Initial Cost to Company  
Land 3,665us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestCentralRoad1250ArlingtonHeightsILMember
Buildings, Improvements & Equipment 32,587us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestCentralRoad1250ArlingtonHeightsILMember
Cost Capitalized Subsequent to Acquisition 2,589snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestCentralRoad1250ArlingtonHeightsILMember
Cost at the end of the period  
Land 3,665us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestCentralRoad1250ArlingtonHeightsILMember
Buildings, Improvements & Equipment 35,176us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestCentralRoad1250ArlingtonHeightsILMember
Total 38,841us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestCentralRoad1250ArlingtonHeightsILMember
Accumulated Depreciation 16,949us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestCentralRoad1250ArlingtonHeightsILMember
1450 Busch Parkway, Buffalo Grove, IL  
Initial Cost to Company  
Land 3,800us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BuschParkway1450BuffaloGroveILMember
Buildings, Improvements & Equipment 11,456us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BuschParkway1450BuffaloGroveILMember
Cost Capitalized Subsequent to Acquisition 169snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BuschParkway1450BuffaloGroveILMember
Cost at the end of the period  
Land 3,800us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BuschParkway1450BuffaloGroveILMember
Buildings, Improvements & Equipment 11,625us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BuschParkway1450BuffaloGroveILMember
Total 15,425us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BuschParkway1450BuffaloGroveILMember
Accumulated Depreciation 1,235us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BuschParkway1450BuffaloGroveILMember
7130 Crimson Ridge Drive, Rockford, IL  
Initial Cost to Company  
Land 200us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrimsonRidgeDrive7130RockfordILMember
Buildings, Improvements & Equipment 7,300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrimsonRidgeDrive7130RockfordILMember
Cost Capitalized Subsequent to Acquisition 28snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrimsonRidgeDrive7130RockfordILMember
Cost at the end of the period  
Land 200us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrimsonRidgeDrive7130RockfordILMember
Buildings, Improvements & Equipment 7,328us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrimsonRidgeDrive7130RockfordILMember
Total 7,528us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrimsonRidgeDrive7130RockfordILMember
Accumulated Depreciation 744us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrimsonRidgeDrive7130RockfordILMember
1220 Lakeview Drive, Romeoville, IL  
Initial Cost to Company  
Land 1,120us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewDrive1220RomeovilleILMember
Buildings, Improvements & Equipment 19,582us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewDrive1220RomeovilleILMember
Cost at the end of the period  
Land 1,120us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewDrive1220RomeovilleILMember
Buildings, Improvements & Equipment 19,582us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewDrive1220RomeovilleILMember
Total 20,702us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewDrive1220RomeovilleILMember
Accumulated Depreciation 3,121us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeviewDrive1220RomeovilleILMember
900 Southwind Road, Springfield, IL  
Initial Cost to Company  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthwindRoad900SpringfieldILMember
Buildings, Improvements & Equipment 6,744us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthwindRoad900SpringfieldILMember
Cost Capitalized Subsequent to Acquisition 1,015snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthwindRoad900SpringfieldILMember
Cost at the end of the period  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthwindRoad900SpringfieldILMember
Buildings, Improvements & Equipment 7,759us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthwindRoad900SpringfieldILMember
Total 8,059us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthwindRoad900SpringfieldILMember
Accumulated Depreciation 1,749us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthwindRoad900SpringfieldILMember
1615 Lakeside Drive, Waukegan, IL  
Initial Cost to Company  
Land 2,700us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakesideDrive1615WaukeganILMember
Buildings, Improvements & Equipment 9,590us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakesideDrive1615WaukeganILMember
Cost Capitalized Subsequent to Acquisition 161snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakesideDrive1615WaukeganILMember
Cost at the end of the period  
Land 2,700us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakesideDrive1615WaukeganILMember
Buildings, Improvements & Equipment 9,751us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakesideDrive1615WaukeganILMember
Total 12,451us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakesideDrive1615WaukeganILMember
Accumulated Depreciation 786us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakesideDrive1615WaukeganILMember
1675 Lakeside Drive, Waukegan, IL  
Initial Cost to Company  
Land 2,420us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakesideDrive1675WaukeganILMember
Buildings, Improvements & Equipment 9,382us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakesideDrive1675WaukeganILMember
Cost Capitalized Subsequent to Acquisition 38snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakesideDrive1675WaukeganILMember
Cost at the end of the period  
Land 2,420us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakesideDrive1675WaukeganILMember
Buildings, Improvements & Equipment 9,420us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakesideDrive1675WaukeganILMember
Total 11,840us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakesideDrive1675WaukeganILMember
Accumulated Depreciation 764us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakesideDrive1675WaukeganILMember
406 Smith Drive, Auburn (4), IN  
Real Estate And Accumulated Depreciation  
Encumbrances 6,391us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SmithDrive406AuburnINMember
Initial Cost to Company  
Land 380us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SmithDrive406AuburnINMember
Buildings, Improvements & Equipment 8,246us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SmithDrive406AuburnINMember
Cost Capitalized Subsequent to Acquisition 40snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SmithDrive406AuburnINMember
Cost at the end of the period  
Land 380us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SmithDrive406AuburnINMember
Buildings, Improvements & Equipment 8,286us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SmithDrive406AuburnINMember
Total 8,666us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SmithDrive406AuburnINMember
Accumulated Depreciation 1,395us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SmithDrive406AuburnINMember
6990 East County Road 100 North, Avon (4), IN  
Real Estate And Accumulated Depreciation  
Encumbrances 9,140us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastCountyRoad100North6990AvonINMember
Initial Cost to Company  
Land 850us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastCountyRoad100North6990AvonINMember
Buildings, Improvements & Equipment 11,888us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastCountyRoad100North6990AvonINMember
Cost Capitalized Subsequent to Acquisition 216snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastCountyRoad100North6990AvonINMember
Cost at the end of the period  
Land 850us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastCountyRoad100North6990AvonINMember
Buildings, Improvements & Equipment 12,104us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastCountyRoad100North6990AvonINMember
Total 12,954us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastCountyRoad100North6990AvonINMember
Accumulated Depreciation 2,027us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastCountyRoad100North6990AvonINMember
2455 Tamarack Trail, Bloomington, IN  
Initial Cost to Company  
Land 5,400us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TamarackTrail2455BloomingtonINMember
Buildings, Improvements & Equipment 25,129us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TamarackTrail2455BloomingtonINMember
Cost Capitalized Subsequent to Acquisition 4,549snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TamarackTrail2455BloomingtonINMember
Cost at the end of the period  
Land 5,400us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TamarackTrail2455BloomingtonINMember
Buildings, Improvements & Equipment 29,678us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TamarackTrail2455BloomingtonINMember
Total 35,078us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TamarackTrail2455BloomingtonINMember
Accumulated Depreciation 4,184us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_TamarackTrail2455BloomingtonINMember
701 East County Line Road, Greenwood, IN  
Initial Cost to Company  
Land 1,830us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastCountyLineRoad701GreenwoodINMember
Buildings, Improvements & Equipment 14,303us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastCountyLineRoad701GreenwoodINMember
Cost Capitalized Subsequent to Acquisition 103snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastCountyLineRoad701GreenwoodINMember
Cost at the end of the period  
Land 1,830us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastCountyLineRoad701GreenwoodINMember
Buildings, Improvements & Equipment 14,406us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastCountyLineRoad701GreenwoodINMember
Total 16,236us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastCountyLineRoad701GreenwoodINMember
Accumulated Depreciation 1,110us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastCountyLineRoad701GreenwoodINMember
8505 Woodfield Crossing Boulevard, Indianapolis (4), IN  
Real Estate And Accumulated Depreciation  
Encumbrances 24,137us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WoodfieldCrossingBoulevard8505IndianapolisINMember
Initial Cost to Company  
Land 2,785us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WoodfieldCrossingBoulevard8505IndianapolisINMember
Buildings, Improvements & Equipment 16,396us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WoodfieldCrossingBoulevard8505IndianapolisINMember
Cost Capitalized Subsequent to Acquisition 5,668snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WoodfieldCrossingBoulevard8505IndianapolisINMember
Cost at the end of the period  
Land 2,785us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WoodfieldCrossingBoulevard8505IndianapolisINMember
Buildings, Improvements & Equipment 22,064us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WoodfieldCrossingBoulevard8505IndianapolisINMember
Total 24,849us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WoodfieldCrossingBoulevard8505IndianapolisINMember
Accumulated Depreciation 7,475us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WoodfieldCrossingBoulevard8505IndianapolisINMember
603 Saint Joseph Drive, Kokomo (4), IN  
Real Estate And Accumulated Depreciation  
Encumbrances 4,052us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SaintJosephDrive603KokomoINMember
Initial Cost to Company  
Land 220us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SaintJosephDrive603KokomoINMember
Buildings, Improvements & Equipment 5,899us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SaintJosephDrive603KokomoINMember
Cost Capitalized Subsequent to Acquisition 163snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SaintJosephDrive603KokomoINMember
Cost at the end of the period  
Land 220us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SaintJosephDrive603KokomoINMember
Buildings, Improvements & Equipment 6,062us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SaintJosephDrive603KokomoINMember
Total 6,282us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SaintJosephDrive603KokomoINMember
Accumulated Depreciation 1,040us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SaintJosephDrive603KokomoINMember
1211 Longwood Drive, La Porte (4), IN  
Real Estate And Accumulated Depreciation  
Encumbrances 4,465us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LongwoodDrive1211LaPorteINMember
Initial Cost to Company  
Land 770us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LongwoodDrive1211LaPorteINMember
Buildings, Improvements & Equipment 5,550us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LongwoodDrive1211LaPorteINMember
Cost Capitalized Subsequent to Acquisition 35snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LongwoodDrive1211LaPorteINMember
Cost at the end of the period  
Land 770us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LongwoodDrive1211LaPorteINMember
Buildings, Improvements & Equipment 5,585us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LongwoodDrive1211LaPorteINMember
Total 6,355us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LongwoodDrive1211LaPorteINMember
Accumulated Depreciation 983us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LongwoodDrive1211LaPorteINMember
1590 West Timberview Drive, Marion (4), IN  
Real Estate And Accumulated Depreciation  
Encumbrances 3,767us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestTimberviewDrive1590MarionINMember
Initial Cost to Company  
Land 410us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestTimberviewDrive1590MarionINMember
Buildings, Improvements & Equipment 5,409us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestTimberviewDrive1590MarionINMember
Cost Capitalized Subsequent to Acquisition 209snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestTimberviewDrive1590MarionINMember
Cost at the end of the period  
Land 410us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestTimberviewDrive1590MarionINMember
Buildings, Improvements & Equipment 5,618us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestTimberviewDrive1590MarionINMember
Total 6,028us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestTimberviewDrive1590MarionINMember
Accumulated Depreciation 974us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestTimberviewDrive1590MarionINMember
1473 East McKay Road, Shelbyville (4), IN  
Real Estate And Accumulated Depreciation  
Encumbrances 3,632us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMcKayRoad1473ShelbyvilleINMember
Initial Cost to Company  
Land 190us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMcKayRoad1473ShelbyvilleINMember
Buildings, Improvements & Equipment 5,328us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMcKayRoad1473ShelbyvilleINMember
Cost Capitalized Subsequent to Acquisition 79snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMcKayRoad1473ShelbyvilleINMember
Cost at the end of the period  
Land 190us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMcKayRoad1473ShelbyvilleINMember
Buildings, Improvements & Equipment 5,407us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMcKayRoad1473ShelbyvilleINMember
Total 5,597us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMcKayRoad1473ShelbyvilleINMember
Accumulated Depreciation 934us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMcKayRoad1473ShelbyvilleINMember
17441 State Rd. #23 (aka 17490 E. Douglas Rd.), South Bend, IN  
Initial Cost to Company  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateRd23aka17490EDouglasRd17441SouthBendINMember
Buildings, Improvements & Equipment 3,107us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateRd23aka17490EDouglasRd17441SouthBendINMember
Cost at the end of the period  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateRd23aka17490EDouglasRd17441SouthBendINMember
Buildings, Improvements & Equipment 3,107us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateRd23aka17490EDouglasRd17441SouthBendINMember
Total 3,507us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateRd23aka17490EDouglasRd17441SouthBendINMember
Accumulated Depreciation 1,048us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateRd23aka17490EDouglasRd17441SouthBendINMember
222 South 25th Street, Terra Haute (4), IN  
Real Estate And Accumulated Depreciation  
Encumbrances 10,618us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South25thStreet222TerraHauteINMember
Initial Cost to Company  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South25thStreet222TerraHauteINMember
Buildings, Improvements & Equipment 13,115us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South25thStreet222TerraHauteINMember
Cost Capitalized Subsequent to Acquisition 64snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South25thStreet222TerraHauteINMember
Cost at the end of the period  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South25thStreet222TerraHauteINMember
Buildings, Improvements & Equipment 13,179us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South25thStreet222TerraHauteINMember
Total 13,479us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South25thStreet222TerraHauteINMember
Accumulated Depreciation 2,252us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South25thStreet222TerraHauteINMember
150 Fox Ridge Drive, Vincennes (4), IN  
Real Estate And Accumulated Depreciation  
Encumbrances 2,622us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoxRidgeDrive150VincennesINMember
Initial Cost to Company  
Land 110us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoxRidgeDrive150VincennesINMember
Buildings, Improvements & Equipment 3,603us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoxRidgeDrive150VincennesINMember
Cost Capitalized Subsequent to Acquisition 1,113snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoxRidgeDrive150VincennesINMember
Cost at the end of the period  
Land 110us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoxRidgeDrive150VincennesINMember
Buildings, Improvements & Equipment 4,716us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoxRidgeDrive150VincennesINMember
Total 4,826us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoxRidgeDrive150VincennesINMember
Accumulated Depreciation 705us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FoxRidgeDrive150VincennesINMember
510 W. 7th Street, Ellinwood, KS  
Initial Cost to Company  
Land 130us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_W7thStreet510EllinwoodKSMember
Buildings, Improvements & Equipment 1,137us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_W7thStreet510EllinwoodKSMember
Cost Capitalized Subsequent to Acquisition 497snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_W7thStreet510EllinwoodKSMember
Cost at the end of the period  
Land 130us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_W7thStreet510EllinwoodKSMember
Buildings, Improvements & Equipment 1,634us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_W7thStreet510EllinwoodKSMember
Total 1,764us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_W7thStreet510EllinwoodKSMember
Accumulated Depreciation 843us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_W7thStreet510EllinwoodKSMember
1501 Inverness Drive, Lawrence, KS  
Initial Cost to Company  
Land 1,600us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_InvernessDrive1501LawrenceKSMember
Buildings, Improvements & Equipment 18,565us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_InvernessDrive1501LawrenceKSMember
Cost Capitalized Subsequent to Acquisition 285snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_InvernessDrive1501LawrenceKSMember
Cost at the end of the period  
Land 1,600us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_InvernessDrive1501LawrenceKSMember
Buildings, Improvements & Equipment 18,850us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_InvernessDrive1501LawrenceKSMember
Total 20,450us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_InvernessDrive1501LawrenceKSMember
Accumulated Depreciation 2,833us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_InvernessDrive1501LawrenceKSMember
3501 West 95th Street, Overland Park (4), KS  
Real Estate And Accumulated Depreciation  
Encumbrances 19,841us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West95thStreet3501OverlandParkKSMember
Initial Cost to Company  
Land 2,568us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West95thStreet3501OverlandParkKSMember
Buildings, Improvements & Equipment 15,140us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West95thStreet3501OverlandParkKSMember
Cost Capitalized Subsequent to Acquisition 3,715snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West95thStreet3501OverlandParkKSMember
Cost at the end of the period  
Land 2,568us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West95thStreet3501OverlandParkKSMember
Buildings, Improvements & Equipment 18,855us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West95thStreet3501OverlandParkKSMember
Total 21,423us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West95thStreet3501OverlandParkKSMember
Accumulated Depreciation 6,784us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West95thStreet3501OverlandParkKSMember
6555 West 75th Street , Overland Park, KS  
Initial Cost to Company  
Land 1,274us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West75thStreet6555OverlandParkKSMember
Buildings, Improvements & Equipment 1,126us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West75thStreet6555OverlandParkKSMember
Cost Capitalized Subsequent to Acquisition 12,400snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West75thStreet6555OverlandParkKSMember
Cost at the end of the period  
Land 1,274us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West75thStreet6555OverlandParkKSMember
Buildings, Improvements & Equipment 13,526us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West75thStreet6555OverlandParkKSMember
Total 14,800us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West75thStreet6555OverlandParkKSMember
Accumulated Depreciation 4,617us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_West75thStreet6555OverlandParkKSMember
981 Campbell Lane, Bowling Green, KY  
Initial Cost to Company  
Land 365us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CampbellLane981BowlingGreenKYMember
Buildings, Improvements & Equipment 4,345us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CampbellLane981BowlingGreenKYMember
Cost Capitalized Subsequent to Acquisition 487snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CampbellLane981BowlingGreenKYMember
Cost at the end of the period  
Land 365us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CampbellLane981BowlingGreenKYMember
Buildings, Improvements & Equipment 4,832us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CampbellLane981BowlingGreenKYMember
Total 5,197us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CampbellLane981BowlingGreenKYMember
Accumulated Depreciation 1,324us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CampbellLane981BowlingGreenKYMember
102 Leonardwood, Frankfort, KY  
Initial Cost to Company  
Land 560us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Leonardwood102FrankfortKYMember
Buildings, Improvements & Equipment 8,282us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Leonardwood102FrankfortKYMember
Cost Capitalized Subsequent to Acquisition 1,186snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Leonardwood102FrankfortKYMember
Cost at the end of the period  
Land 560us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Leonardwood102FrankfortKYMember
Buildings, Improvements & Equipment 9,468us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Leonardwood102FrankfortKYMember
Total 10,028us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Leonardwood102FrankfortKYMember
Accumulated Depreciation 2,123us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Leonardwood102FrankfortKYMember
4190 Lafayette Road, Hopkinsville, KY  
Initial Cost to Company  
Land 316us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LafayetteRoad4190HopkinsvilleKYMember
Buildings, Improvements & Equipment 3,761us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LafayetteRoad4190HopkinsvilleKYMember
Cost Capitalized Subsequent to Acquisition 189snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LafayetteRoad4190HopkinsvilleKYMember
Cost at the end of the period  
Land 316us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LafayetteRoad4190HopkinsvilleKYMember
Buildings, Improvements & Equipment 3,950us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LafayetteRoad4190HopkinsvilleKYMember
Total 4,266us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LafayetteRoad4190HopkinsvilleKYMember
Accumulated Depreciation 1,113us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LafayetteRoad4190HopkinsvilleKYMember
690 Mason Headley Road, Lexington (5), KY  
Real Estate And Accumulated Depreciation  
Encumbrances 10,425us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MasonHeadleyRoad690LexingtonKYMember
Initial Cost to Company  
Buildings, Improvements & Equipment 10,848us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MasonHeadleyRoad690LexingtonKYMember
Cost Capitalized Subsequent to Acquisition 11,362snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MasonHeadleyRoad690LexingtonKYMember
Cost at the end of the period  
Buildings, Improvements & Equipment 22,210us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MasonHeadleyRoad690LexingtonKYMember
Total 22,210us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MasonHeadleyRoad690LexingtonKYMember
Accumulated Depreciation 10,409us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MasonHeadleyRoad690LexingtonKYMember
700 Mason Headley Road, Lexington (5), KY  
Real Estate And Accumulated Depreciation  
Encumbrances 2,345us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MasonHeadleyRoad700LexingtonKYMember
Initial Cost to Company  
Buildings, Improvements & Equipment 6,394us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MasonHeadleyRoad700LexingtonKYMember
Cost Capitalized Subsequent to Acquisition 5,578snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MasonHeadleyRoad700LexingtonKYMember
Cost at the end of the period  
Buildings, Improvements & Equipment 11,972us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MasonHeadleyRoad700LexingtonKYMember
Total 11,972us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MasonHeadleyRoad700LexingtonKYMember
Accumulated Depreciation 5,536us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MasonHeadleyRoad700LexingtonKYMember
200 Brookside Drive, Louisville (4), KY  
Real Estate And Accumulated Depreciation  
Encumbrances 29,193us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrooksideDrive200LouisvilleKYMember
Initial Cost to Company  
Land 3,524us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrooksideDrive200LouisvilleKYMember
Buildings, Improvements & Equipment 20,779us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrooksideDrive200LouisvilleKYMember
Cost Capitalized Subsequent to Acquisition 5,722snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrooksideDrive200LouisvilleKYMember
Cost at the end of the period  
Land 3,524us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrooksideDrive200LouisvilleKYMember
Buildings, Improvements & Equipment 26,501us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrooksideDrive200LouisvilleKYMember
Total 30,025us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrooksideDrive200LouisvilleKYMember
Accumulated Depreciation 9,833us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrooksideDrive200LouisvilleKYMember
1517 West Broadway, Mayfield, KY  
Initial Cost to Company  
Land 268us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestBroadway1517MayfieldKYMember
Buildings, Improvements & Equipment 2,730us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestBroadway1517MayfieldKYMember
Cost Capitalized Subsequent to Acquisition 736snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestBroadway1517MayfieldKYMember
Cost at the end of the period  
Land 268us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestBroadway1517MayfieldKYMember
Buildings, Improvements & Equipment 3,466us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestBroadway1517MayfieldKYMember
Total 3,734us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestBroadway1517MayfieldKYMember
Accumulated Depreciation 977us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestBroadway1517MayfieldKYMember
1700 Elmdale Road, Paducah, KY  
Initial Cost to Company  
Land 450us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmdaleRoad1700PaducahKYMember
Buildings, Improvements & Equipment 5,358us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmdaleRoad1700PaducahKYMember
Cost Capitalized Subsequent to Acquisition 822snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmdaleRoad1700PaducahKYMember
Cost at the end of the period  
Land 450us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmdaleRoad1700PaducahKYMember
Buildings, Improvements & Equipment 6,180us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmdaleRoad1700PaducahKYMember
Total 6,630us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmdaleRoad1700PaducahKYMember
Accumulated Depreciation 1,654us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmdaleRoad1700PaducahKYMember
100 Neighborly Way, Somerset, KY  
Initial Cost to Company  
Land 200us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NeighborlyWay100SomersetKYMember
Buildings, Improvements & Equipment 4,919us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NeighborlyWay100SomersetKYMember
Cost Capitalized Subsequent to Acquisition 258snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NeighborlyWay100SomersetKYMember
Cost at the end of the period  
Land 200us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NeighborlyWay100SomersetKYMember
Buildings, Improvements & Equipment 5,177us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NeighborlyWay100SomersetKYMember
Total 5,377us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NeighborlyWay100SomersetKYMember
Accumulated Depreciation 1,051us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NeighborlyWay100SomersetKYMember
35 Milbury St, Auburn, MA  
Initial Cost to Company  
Land 1,510us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MilburySt35AuburnMAMember
Buildings, Improvements & Equipment 7,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MilburySt35AuburnMAMember
Cost Capitalized Subsequent to Acquisition 310snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MilburySt35AuburnMAMember
Cost at the end of the period  
Land 1,510us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MilburySt35AuburnMAMember
Buildings, Improvements & Equipment 7,310us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MilburySt35AuburnMAMember
Total 8,820us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MilburySt35AuburnMAMember
Accumulated Depreciation 1,208us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MilburySt35AuburnMAMember
1295 Boylston Street, Boston, MA  
Initial Cost to Company  
Land 7,600us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoylstonStreet1295BostonMAMember
Buildings, Improvements & Equipment 18,140us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoylstonStreet1295BostonMAMember
Cost Capitalized Subsequent to Acquisition 732snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoylstonStreet1295BostonMAMember
Cost at the end of the period  
Land 7,600us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoylstonStreet1295BostonMAMember
Buildings, Improvements & Equipment 18,872us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoylstonStreet1295BostonMAMember
Total 26,472us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoylstonStreet1295BostonMAMember
Accumulated Depreciation 1,783us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoylstonStreet1295BostonMAMember
50 Northern Ave/11 Fan Pier Blvd, Boston,MA  
Initial Cost to Company  
Land 52,643us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthernAve50AndFanPierBlvd11BostonMMember
Buildings, Improvements & Equipment 784,954us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthernAve50AndFanPierBlvd11BostonMMember
Cost Capitalized Subsequent to Acquisition 26snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthernAve50AndFanPierBlvd11BostonMMember
Cost at the end of the period  
Land 52,644us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthernAve50AndFanPierBlvd11BostonMMember
Buildings, Improvements & Equipment 784,979us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthernAve50AndFanPierBlvd11BostonMMember
Total 837,623us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthernAve50AndFanPierBlvd11BostonMMember
Accumulated Depreciation 13,098us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthernAve50AndFanPierBlvd11BostonMMember
549 Albany Street, Boston, MA  
Initial Cost to Company  
Land 4,576us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AlbanyStreet549BostonMAMember
Buildings, Improvements & Equipment 45,029us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AlbanyStreet549BostonMAMember
Cost at the end of the period  
Land 4,569us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AlbanyStreet549BostonMAMember
Buildings, Improvements & Equipment 45,036us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AlbanyStreet549BostonMAMember
Total 49,605us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AlbanyStreet549BostonMAMember
Accumulated Depreciation 1,501us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AlbanyStreet549BostonMAMember
370 Lunenburg St, Fitchburg, MA  
Initial Cost to Company  
Land 330us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LunenburgSt370FitchburgMAMember
Buildings, Improvements & Equipment 3,361us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LunenburgSt370FitchburgMAMember
Cost Capitalized Subsequent to Acquisition 32snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LunenburgSt370FitchburgMAMember
Cost at the end of the period  
Land 330us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LunenburgSt370FitchburgMAMember
Buildings, Improvements & Equipment 3,393us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LunenburgSt370FitchburgMAMember
Total 3,723us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LunenburgSt370FitchburgMAMember
Accumulated Depreciation 541us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LunenburgSt370FitchburgMAMember
165 Mill St, Leominster, MA  
Initial Cost to Company  
Land 1,520us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MillSt165LeominsterMAMember
Buildings, Improvements & Equipment 8,703us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MillSt165LeominsterMAMember
Cost Capitalized Subsequent to Acquisition 718snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MillSt165LeominsterMAMember
Cost at the end of the period  
Land 1,520us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MillSt165LeominsterMAMember
Buildings, Improvements & Equipment 9,421us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MillSt165LeominsterMAMember
Total 10,941us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MillSt165LeominsterMAMember
Accumulated Depreciation 1,555us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MillSt165LeominsterMAMember
4 Maguire Road, Lexington, MA  
Initial Cost to Company  
Land 3,600us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MaguireRoad4LexingtonMAMember
Buildings, Improvements & Equipment 15,555us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MaguireRoad4LexingtonMAMember
Cost Capitalized Subsequent to Acquisition 1,321snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MaguireRoad4LexingtonMAMember
Impairment (7,255)snh_RealEstateAndAccumulatedDepreciationCarryingAmountOfImpairment
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MaguireRoad4LexingtonMAMember
Cost at the end of the period  
Land 3,600us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MaguireRoad4LexingtonMAMember
Buildings, Improvements & Equipment 9,621us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MaguireRoad4LexingtonMAMember
Total 13,221us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MaguireRoad4LexingtonMAMember
Accumulated Depreciation 1,731us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MaguireRoad4LexingtonMAMember
100 Hampshire Street, Mansfield, MA  
Initial Cost to Company  
Land 2,090us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet100MansfieldMAMember
Buildings, Improvements & Equipment 8,215us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet100MansfieldMAMember
Cost Capitalized Subsequent to Acquisition 265snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet100MansfieldMAMember
Cost at the end of the period  
Land 2,182us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet100MansfieldMAMember
Buildings, Improvements & Equipment 8,388us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet100MansfieldMAMember
Total 10,570us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet100MansfieldMAMember
Accumulated Depreciation 822us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet100MansfieldMAMember
15 Hampshire Street, Mansfield, MA  
Initial Cost to Company  
Land 1,360us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet15MansfieldMAMember
Buildings, Improvements & Equipment 7,326us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet15MansfieldMAMember
Cost Capitalized Subsequent to Acquisition 108snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet15MansfieldMAMember
Cost at the end of the period  
Land 1,360us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet15MansfieldMAMember
Buildings, Improvements & Equipment 7,434us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet15MansfieldMAMember
Total 8,794us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet15MansfieldMAMember
Accumulated Depreciation 743us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet15MansfieldMAMember
5 Hampshire Street, Mansfield, MA  
Initial Cost to Company  
Land 1,190us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet5MansfieldMAMember
Buildings, Improvements & Equipment 5,737us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet5MansfieldMAMember
Cost at the end of the period  
Land 1,190us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet5MansfieldMAMember
Buildings, Improvements & Equipment 5,737us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet5MansfieldMAMember
Total 6,927us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet5MansfieldMAMember
Accumulated Depreciation 574us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HampshireStreet5MansfieldMAMember
176 West St, Milford, MA  
Initial Cost to Company  
Land 510us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSt176MilfordMAMember
Buildings, Improvements & Equipment 3,039us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSt176MilfordMAMember
Cost Capitalized Subsequent to Acquisition 595snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSt176MilfordMAMember
Cost at the end of the period  
Land 510us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSt176MilfordMAMember
Buildings, Improvements & Equipment 3,634us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSt176MilfordMAMember
Total 4,144us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSt176MilfordMAMember
Accumulated Depreciation 767us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestSt176MilfordMAMember
108 Elm St, Millbury, MA  
Initial Cost to Company  
Land 160us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmSt108MillburyMAMember
Buildings, Improvements & Equipment 768us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmSt108MillburyMAMember
Cost Capitalized Subsequent to Acquisition (1)snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmSt108MillburyMAMember
Cost at the end of the period  
Land 160us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmSt108MillburyMAMember
Buildings, Improvements & Equipment 767us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmSt108MillburyMAMember
Total 927us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmSt108MillburyMAMember
Accumulated Depreciation 123us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmSt108MillburyMAMember
30 Newcrossing Road, Reading (4), MA  
Real Estate And Accumulated Depreciation  
Encumbrances 11,059us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NewcrossingRoad30ReadingMAMember
Initial Cost to Company  
Land 1,443us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NewcrossingRoad30ReadingMAMember
Buildings, Improvements & Equipment 14,153us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NewcrossingRoad30ReadingMAMember
Cost Capitalized Subsequent to Acquisition 50snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NewcrossingRoad30ReadingMAMember
Cost at the end of the period  
Land 1,443us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NewcrossingRoad30ReadingMAMember
Buildings, Improvements & Equipment 14,203us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NewcrossingRoad30ReadingMAMember
Total 15,646us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NewcrossingRoad30ReadingMAMember
Accumulated Depreciation 800us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NewcrossingRoad30ReadingMAMember
407 Main St, Spencer, MA  
Initial Cost to Company  
Land 270us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MainSt407SpencerMAMember
Buildings, Improvements & Equipment 2,607us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MainSt407SpencerMAMember
Cost Capitalized Subsequent to Acquisition 476snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MainSt407SpencerMAMember
Cost at the end of the period  
Land 270us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MainSt407SpencerMAMember
Buildings, Improvements & Equipment 3,083us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MainSt407SpencerMAMember
Total 3,353us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MainSt407SpencerMAMember
Accumulated Depreciation 598us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MainSt407SpencerMAMember
106 East Main, Westborough, MA  
Initial Cost to Company  
Land 920us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMain106WestboroughMAMember
Buildings, Improvements & Equipment 6,956us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMain106WestboroughMAMember
Cost Capitalized Subsequent to Acquisition 126snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMain106WestboroughMAMember
Cost at the end of the period  
Land 920us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMain106WestboroughMAMember
Buildings, Improvements & Equipment 7,082us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMain106WestboroughMAMember
Total 8,002us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMain106WestboroughMAMember
Accumulated Depreciation 1,137us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMain106WestboroughMAMember
112 East Main, Westborough, MA  
Initial Cost to Company  
Land 230us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMain112WestboroughMAMember
Buildings, Improvements & Equipment 135us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMain112WestboroughMAMember
Cost at the end of the period  
Land 230us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMain112WestboroughMAMember
Buildings, Improvements & Equipment 135us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMain112WestboroughMAMember
Total 365us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMain112WestboroughMAMember
Accumulated Depreciation 23us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastMain112WestboroughMAMember
299 Cambridge Street, Winchester, MA  
Initial Cost to Company  
Land 3,218us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CambridgeStreet299WinchesterMAMember
Buildings, Improvements & Equipment 18,988us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CambridgeStreet299WinchesterMAMember
Cost Capitalized Subsequent to Acquisition 10,191snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CambridgeStreet299WinchesterMAMember
Cost at the end of the period  
Land 3,218us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CambridgeStreet299WinchesterMAMember
Buildings, Improvements & Equipment 29,179us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CambridgeStreet299WinchesterMAMember
Total 32,397us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CambridgeStreet299WinchesterMAMember
Accumulated Depreciation 8,843us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CambridgeStreet299WinchesterMAMember
135 Goldstar Blvd, Worcester, MA  
Initial Cost to Company  
Land 865us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GoldstarBlvd135WorcesterMAMember
Buildings, Improvements & Equipment 10,912us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GoldstarBlvd135WorcesterMAMember
Cost Capitalized Subsequent to Acquisition 1,136snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GoldstarBlvd135WorcesterMAMember
Cost at the end of the period  
Land 865us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GoldstarBlvd135WorcesterMAMember
Buildings, Improvements & Equipment 12,048us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GoldstarBlvd135WorcesterMAMember
Total 12,913us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GoldstarBlvd135WorcesterMAMember
Accumulated Depreciation 1,852us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GoldstarBlvd135WorcesterMAMember
191 May St, Worcester, MA  
Initial Cost to Company  
Land 730us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MaySt191WorcesterMAMember
Buildings, Improvements & Equipment 3,634us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MaySt191WorcesterMAMember
Cost Capitalized Subsequent to Acquisition 42snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MaySt191WorcesterMAMember
Cost at the end of the period  
Land 730us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MaySt191WorcesterMAMember
Buildings, Improvements & Equipment 3,676us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MaySt191WorcesterMAMember
Total 4,406us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MaySt191WorcesterMAMember
Accumulated Depreciation 587us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MaySt191WorcesterMAMember
277 E Mountain, Worcester, MA  
Initial Cost to Company  
Land 191us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EMountain277WorcesterMAMember
Buildings, Improvements & Equipment 2,133us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EMountain277WorcesterMAMember
Cost Capitalized Subsequent to Acquisition 113snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EMountain277WorcesterMAMember
Impairment (889)snh_RealEstateAndAccumulatedDepreciationCarryingAmountOfImpairment
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EMountain277WorcesterMAMember
Cost at the end of the period  
Land 191us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EMountain277WorcesterMAMember
Buildings, Improvements & Equipment 1,357us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EMountain277WorcesterMAMember
Total 1,548us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EMountain277WorcesterMAMember
Accumulated Depreciation 241us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EMountain277WorcesterMAMember
425 N Lake Ave, Worcester, MA  
Initial Cost to Company  
Land 1,200us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NLakeAve425WorcesterMAMember
Buildings, Improvements & Equipment 6,176us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NLakeAve425WorcesterMAMember
Cost Capitalized Subsequent to Acquisition 101snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NLakeAve425WorcesterMAMember
Cost at the end of the period  
Land 1,200us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NLakeAve425WorcesterMAMember
Buildings, Improvements & Equipment 6,277us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NLakeAve425WorcesterMAMember
Total 7,477us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NLakeAve425WorcesterMAMember
Accumulated Depreciation 1,006us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NLakeAve425WorcesterMAMember
630 Plantation St, Worcester, MA  
Initial Cost to Company  
Land 770us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PlantationSt630WorcesterMAMember
Buildings, Improvements & Equipment 10,408us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PlantationSt630WorcesterMAMember
Cost Capitalized Subsequent to Acquisition 528snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PlantationSt630WorcesterMAMember
Cost at the end of the period  
Land 770us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PlantationSt630WorcesterMAMember
Buildings, Improvements & Equipment 10,936us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PlantationSt630WorcesterMAMember
Total 11,706us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PlantationSt630WorcesterMAMember
Accumulated Depreciation 1,838us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PlantationSt630WorcesterMAMember
2717 Riva Road, Annapolis, MD  
Initial Cost to Company  
Land 1,290us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RivaRoad2717AnnapolisMDMember
Buildings, Improvements & Equipment 12,373us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RivaRoad2717AnnapolisMDMember
Cost Capitalized Subsequent to Acquisition 515snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RivaRoad2717AnnapolisMDMember
Cost at the end of the period  
Land 1,290us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RivaRoad2717AnnapolisMDMember
Buildings, Improvements & Equipment 12,888us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RivaRoad2717AnnapolisMDMember
Total 14,178us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RivaRoad2717AnnapolisMDMember
Accumulated Depreciation 2,186us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RivaRoad2717AnnapolisMDMember
658 Boulton Street, Bel Air, MD  
Initial Cost to Company  
Land 4,750us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoultonStreet658BelAirMDMember
Buildings, Improvements & Equipment 16,504us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoultonStreet658BelAirMDMember
Cost Capitalized Subsequent to Acquisition 2snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoultonStreet658BelAirMDMember
Cost at the end of the period  
Land 4,750us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoultonStreet658BelAirMDMember
Buildings, Improvements & Equipment 16,506us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoultonStreet658BelAirMDMember
Total 21,256us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoultonStreet658BelAirMDMember
Accumulated Depreciation 2,940us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BoultonStreet658BelAirMDMember
7600 Laurel Bowie Road, Bowie, MD  
Initial Cost to Company  
Land 408us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LaurelBowieRoad7600BowieMDMember
Buildings, Improvements & Equipment 3,421us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LaurelBowieRoad7600BowieMDMember
Cost Capitalized Subsequent to Acquisition 450snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LaurelBowieRoad7600BowieMDMember
Cost at the end of the period  
Land 408us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LaurelBowieRoad7600BowieMDMember
Buildings, Improvements & Equipment 3,871us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LaurelBowieRoad7600BowieMDMember
Total 4,279us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LaurelBowieRoad7600BowieMDMember
Accumulated Depreciation 1,385us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LaurelBowieRoad7600BowieMDMember
8100 Connecticut Avenue, Chevy Chase (4), MD  
Real Estate And Accumulated Depreciation  
Encumbrances 53,557us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ConnecticutAvenue8100ChevyChaseMDMember
Initial Cost to Company  
Land 15,174us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ConnecticutAvenue8100ChevyChaseMDMember
Buildings, Improvements & Equipment 92,830us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ConnecticutAvenue8100ChevyChaseMDMember
Cost Capitalized Subsequent to Acquisition 2,874snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ConnecticutAvenue8100ChevyChaseMDMember
Cost at the end of the period  
Land 15,175us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ConnecticutAvenue8100ChevyChaseMDMember
Buildings, Improvements & Equipment 95,703us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ConnecticutAvenue8100ChevyChaseMDMember
Total 110,878us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ConnecticutAvenue8100ChevyChaseMDMember
Accumulated Depreciation 7,832us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ConnecticutAvenue8100ChevyChaseMDMember
8220 Snowden River Parkway, Columbia, MD  
Initial Cost to Company  
Land 1,390us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SnowdenRiverParkway8220ColumbiaMDMember
Buildings, Improvements & Equipment 10,303us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SnowdenRiverParkway8220ColumbiaMDMember
Cost Capitalized Subsequent to Acquisition 155snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SnowdenRiverParkway8220ColumbiaMDMember
Cost at the end of the period  
Land 1,390us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SnowdenRiverParkway8220ColumbiaMDMember
Buildings, Improvements & Equipment 10,458us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SnowdenRiverParkway8220ColumbiaMDMember
Total 11,848us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SnowdenRiverParkway8220ColumbiaMDMember
Accumulated Depreciation 1,783us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SnowdenRiverParkway8220ColumbiaMDMember
700 Port Street , Easton, MD  
Initial Cost to Company  
Land 383us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PortStreet700EastonMDMember
Buildings, Improvements & Equipment 4,555us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PortStreet700EastonMDMember
Cost Capitalized Subsequent to Acquisition 2,983snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PortStreet700EastonMDMember
Cost at the end of the period  
Land 383us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PortStreet700EastonMDMember
Buildings, Improvements & Equipment 7,538us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PortStreet700EastonMDMember
Total 7,921us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PortStreet700EastonMDMember
Accumulated Depreciation 2,088us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PortStreet700EastonMDMember
3004 North Ridge Road , Ellicott City (4), MD  
Real Estate And Accumulated Depreciation  
Encumbrances 19,542us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRidgeRoad3004EllicottCityMDMember
Initial Cost to Company  
Land 1,409us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRidgeRoad3004EllicottCityMDMember
Buildings, Improvements & Equipment 22,691us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRidgeRoad3004EllicottCityMDMember
Cost Capitalized Subsequent to Acquisition 6,268snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRidgeRoad3004EllicottCityMDMember
Cost at the end of the period  
Land 1,409us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRidgeRoad3004EllicottCityMDMember
Buildings, Improvements & Equipment 28,959us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRidgeRoad3004EllicottCityMDMember
Total 30,368us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRidgeRoad3004EllicottCityMDMember
Accumulated Depreciation 8,627us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRidgeRoad3004EllicottCityMDMember
1820 Latham Drive , Frederick, MD  
Initial Cost to Company  
Land 385us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LathamDrive1820FrederickMDMember
Buildings, Improvements & Equipment 3,444us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LathamDrive1820FrederickMDMember
Cost Capitalized Subsequent to Acquisition 427snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LathamDrive1820FrederickMDMember
Cost at the end of the period  
Land 385us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LathamDrive1820FrederickMDMember
Buildings, Improvements & Equipment 3,871us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LathamDrive1820FrederickMDMember
Total 4,256us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LathamDrive1820FrederickMDMember
Accumulated Depreciation 1,399us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LathamDrive1820FrederickMDMember
2100A & B Whittier Drive, Frederick, MD  
Initial Cost to Company  
Land 1,260us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AAndBWhittierDrive2100FrederickMDMember
Buildings, Improvements & Equipment 9,464us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AAndBWhittierDrive2100FrederickMDMember
Cost Capitalized Subsequent to Acquisition 933snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AAndBWhittierDrive2100FrederickMDMember
Cost at the end of the period  
Land 1,260us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AAndBWhittierDrive2100FrederickMDMember
Buildings, Improvements & Equipment 10,397us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AAndBWhittierDrive2100FrederickMDMember
Total 11,657us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AAndBWhittierDrive2100FrederickMDMember
Accumulated Depreciation 1,702us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AAndBWhittierDrive2100FrederickMDMember
10114 + 10116 Sharpsburg Pike, Hagerstown, MD  
Initial Cost to Company  
Land 1,040us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SharpsburgPike10114And10116HagerstownMDMember
Buildings, Improvements & Equipment 7,471us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SharpsburgPike10114And10116HagerstownMDMember
Cost Capitalized Subsequent to Acquisition 525snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SharpsburgPike10114And10116HagerstownMDMember
Cost at the end of the period  
Land 1,040us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SharpsburgPike10114And10116HagerstownMDMember
Buildings, Improvements & Equipment 7,996us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SharpsburgPike10114And10116HagerstownMDMember
Total 9,036us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SharpsburgPike10114And10116HagerstownMDMember
Accumulated Depreciation 1,310us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SharpsburgPike10114And10116HagerstownMDMember
4000 Old Court Road, Pikesville, MD  
Initial Cost to Company  
Land 2,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCourtRoad4000PikesvilleMDMember
Buildings, Improvements & Equipment 4,974us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCourtRoad4000PikesvilleMDMember
Cost Capitalized Subsequent to Acquisition 371snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCourtRoad4000PikesvilleMDMember
Cost at the end of the period  
Land 2,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCourtRoad4000PikesvilleMDMember
Buildings, Improvements & Equipment 5,345us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCourtRoad4000PikesvilleMDMember
Total 7,345us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCourtRoad4000PikesvilleMDMember
Accumulated Depreciation 847us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCourtRoad4000PikesvilleMDMember
715 Benfield Road, Severna Park (4), MD  
Real Estate And Accumulated Depreciation  
Encumbrances 8,640us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BenfieldRoad715SevernaParkMDMember
Initial Cost to Company  
Land 229us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BenfieldRoad715SevernaParkMDMember
Buildings, Improvements & Equipment 9,798us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BenfieldRoad715SevernaParkMDMember
Cost Capitalized Subsequent to Acquisition 1,643snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BenfieldRoad715SevernaParkMDMember
Cost at the end of the period  
Land 229us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BenfieldRoad715SevernaParkMDMember
Buildings, Improvements & Equipment 11,441us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BenfieldRoad715SevernaParkMDMember
Total 11,670us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BenfieldRoad715SevernaParkMDMember
Accumulated Depreciation 3,903us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BenfieldRoad715SevernaParkMDMember
14400 Homecrest Road , Silver Spring, MD  
Initial Cost to Company  
Land 1,200us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HomecrestRoad14400SilverSpringMDMember
Buildings, Improvements & Equipment 9,288us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HomecrestRoad14400SilverSpringMDMember
Cost Capitalized Subsequent to Acquisition 6,502snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HomecrestRoad14400SilverSpringMDMember
Cost at the end of the period  
Land 1,200us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HomecrestRoad14400SilverSpringMDMember
Buildings, Improvements & Equipment 15,790us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HomecrestRoad14400SilverSpringMDMember
Total 16,990us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HomecrestRoad14400SilverSpringMDMember
Accumulated Depreciation 4,943us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HomecrestRoad14400SilverSpringMDMember
3701 International Drive, Silver Spring, MD  
Initial Cost to Company  
Land 3,301us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_InternationalDrive3701SilverSpringMDMember
Buildings, Improvements & Equipment 29,065us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_InternationalDrive3701SilverSpringMDMember
Cost Capitalized Subsequent to Acquisition 714snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_InternationalDrive3701SilverSpringMDMember
Cost at the end of the period  
Land 3,301us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_InternationalDrive3701SilverSpringMDMember
Buildings, Improvements & Equipment 29,779us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_InternationalDrive3701SilverSpringMDMember
Total 33,080us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_InternationalDrive3701SilverSpringMDMember
Accumulated Depreciation 15,230us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_InternationalDrive3701SilverSpringMDMember
801 Roeder Road, Unit OU-1, Silver Spring, MD  
Initial Cost to Company  
Land 1,900us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RoederRoadUnitOU1801SilverSpringMDMember
Buildings, Improvements & Equipment 12,858us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RoederRoadUnitOU1801SilverSpringMDMember
Cost Capitalized Subsequent to Acquisition 618snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RoederRoadUnitOU1801SilverSpringMDMember
Cost at the end of the period  
Land 1,900us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RoederRoadUnitOU1801SilverSpringMDMember
Buildings, Improvements & Equipment 13,476us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RoederRoadUnitOU1801SilverSpringMDMember
Total 15,376us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RoederRoadUnitOU1801SilverSpringMDMember
Accumulated Depreciation 876us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RoederRoadUnitOU1801SilverSpringMDMember
720 & 734 N. Pine Road, Hampton, MI  
Initial Cost to Company  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPineRoad720And734HamptonMIMember
Buildings, Improvements & Equipment 2,406us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPineRoad720And734HamptonMIMember
Cost at the end of the period  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPineRoad720And734HamptonMIMember
Buildings, Improvements & Equipment 2,406us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPineRoad720And734HamptonMIMember
Total 2,706us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPineRoad720And734HamptonMIMember
Accumulated Depreciation 813us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPineRoad720And734HamptonMIMember
4004 & 4012 Waldo Road, Midland, MI  
Initial Cost to Company  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaldoRoad4004And4012MidlandMIMember
Buildings, Improvements & Equipment 2,606us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaldoRoad4004And4012MidlandMIMember
Cost at the end of the period  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaldoRoad4004And4012MidlandMIMember
Buildings, Improvements & Equipment 2,606us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaldoRoad4004And4012MidlandMIMember
Total 3,006us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaldoRoad4004And4012MidlandMIMember
Accumulated Depreciation 886us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaldoRoad4004And4012MidlandMIMember
1605 & 1615 Fredericks Drive, Monroe, MI  
Initial Cost to Company  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FredericksDrive1605And1615MonroeMIMember
Buildings, Improvements & Equipment 2,506us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FredericksDrive1605And1615MonroeMIMember
Cost at the end of the period  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FredericksDrive1605And1615MonroeMIMember
Buildings, Improvements & Equipment 2,506us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FredericksDrive1605And1615MonroeMIMember
Total 2,806us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FredericksDrive1605And1615MonroeMIMember
Accumulated Depreciation 849us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FredericksDrive1605And1615MonroeMIMember
3150 & 3100 Old Centre Road, Portage, MI  
Initial Cost to Company  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCentreRoad3150And3100PortageMIMember
Buildings, Improvements & Equipment 2,206us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCentreRoad3150And3100PortageMIMember
Cost at the end of the period  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCentreRoad3150And3100PortageMIMember
Buildings, Improvements & Equipment 2,206us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCentreRoad3150And3100PortageMIMember
Total 2,506us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCentreRoad3150And3100PortageMIMember
Accumulated Depreciation 746us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCentreRoad3150And3100PortageMIMember
2445 & 2485 Mc Carty Road, Saginaw, MI  
Initial Cost to Company  
Land 600us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McCartyRoad2445And2485SaginawMIMember
Buildings, Improvements & Equipment 5,212us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McCartyRoad2445And2485SaginawMIMember
Cost at the end of the period  
Land 600us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McCartyRoad2445And2485SaginawMIMember
Buildings, Improvements & Equipment 5,212us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McCartyRoad2445And2485SaginawMIMember
Total 5,812us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McCartyRoad2445And2485SaginawMIMember
Accumulated Depreciation 1,758us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McCartyRoad2445And2485SaginawMIMember
11855 Ulysses Street NE, Blaine (4), MN  
Real Estate And Accumulated Depreciation  
Encumbrances 9,195us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UlyssesStreetNE11855BlaineMNMember
Initial Cost to Company  
Land 2,774us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UlyssesStreetNE11855BlaineMNMember
Buildings, Improvements & Equipment 9,276us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UlyssesStreetNE11855BlaineMNMember
Cost Capitalized Subsequent to Acquisition 46snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UlyssesStreetNE11855BlaineMNMember
Cost at the end of the period  
Land 2,774us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UlyssesStreetNE11855BlaineMNMember
Buildings, Improvements & Equipment 9,322us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UlyssesStreetNE11855BlaineMNMember
Total 12,096us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UlyssesStreetNE11855BlaineMNMember
Accumulated Depreciation 469us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UlyssesStreetNE11855BlaineMNMember
1305 Corporate Center Drive, Eagan, MN  
Initial Cost to Company  
Land 2,300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CorporateCenterDrive1305EaganMNMember
Buildings, Improvements & Equipment 13,105us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CorporateCenterDrive1305EaganMNMember
Cost Capitalized Subsequent to Acquisition 105snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CorporateCenterDrive1305EaganMNMember
Cost at the end of the period  
Land 2,300us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CorporateCenterDrive1305EaganMNMember
Buildings, Improvements & Equipment 13,210us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CorporateCenterDrive1305EaganMNMember
Total 15,510us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CorporateCenterDrive1305EaganMNMember
Accumulated Depreciation 1,318us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CorporateCenterDrive1305EaganMNMember
1201 Northland Drive, Mendota Heights, MN  
Initial Cost to Company  
Land 1,220us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthlandDrive1201MendotaHeightsMNMember
Buildings, Improvements & Equipment 10,208us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthlandDrive1201MendotaHeightsMNMember
Cost Capitalized Subsequent to Acquisition 95snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthlandDrive1201MendotaHeightsMNMember
Cost at the end of the period  
Land 1,220us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthlandDrive1201MendotaHeightsMNMember
Buildings, Improvements & Equipment 10,303us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthlandDrive1201MendotaHeightsMNMember
Total 11,523us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthlandDrive1201MendotaHeightsMNMember
Accumulated Depreciation 1,004us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthlandDrive1201MendotaHeightsMNMember
20500/20600 South Diamond Lake Road, Rogers, MN  
Initial Cost to Company  
Land 2,760us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthDiamondLakeRoad20500And20600RogersMNMember
Buildings, Improvements & Equipment 45,789us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthDiamondLakeRoad20500And20600RogersMNMember
Cost Capitalized Subsequent to Acquisition 1,037snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthDiamondLakeRoad20500And20600RogersMNMember
Cost at the end of the period  
Land 2,760us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthDiamondLakeRoad20500And20600RogersMNMember
Buildings, Improvements & Equipment 46,826us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthDiamondLakeRoad20500And20600RogersMNMember
Total 49,586us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthDiamondLakeRoad20500And20600RogersMNMember
Accumulated Depreciation 8,278us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthDiamondLakeRoad20500And20600RogersMNMember
2200 County Road C West, Roseville, MN  
Initial Cost to Company  
Land 590us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CountyRoadCWest2200RosevilleMNMember
Buildings, Improvements & Equipment 702us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CountyRoadCWest2200RosevilleMNMember
Cost Capitalized Subsequent to Acquisition 173snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CountyRoadCWest2200RosevilleMNMember
Cost at the end of the period  
Land 590us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CountyRoadCWest2200RosevilleMNMember
Buildings, Improvements & Equipment 875us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CountyRoadCWest2200RosevilleMNMember
Total 1,465us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CountyRoadCWest2200RosevilleMNMember
Accumulated Depreciation 58us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CountyRoadCWest2200RosevilleMNMember
4166 Lexington Avenue N, Shoreview, MN  
Initial Cost to Company  
Land 1,300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LexingtonAvenueN4166ShoreviewMNMember
Buildings, Improvements & Equipment 4,547us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LexingtonAvenueN4166ShoreviewMNMember
Cost Capitalized Subsequent to Acquisition 159snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LexingtonAvenueN4166ShoreviewMNMember
Cost at the end of the period  
Land 1,320us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LexingtonAvenueN4166ShoreviewMNMember
Buildings, Improvements & Equipment 4,686us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LexingtonAvenueN4166ShoreviewMNMember
Total 6,006us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LexingtonAvenueN4166ShoreviewMNMember
Accumulated Depreciation 421us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LexingtonAvenueN4166ShoreviewMNMember
1365 Crestridge Lane, West St. Paul, MN  
Initial Cost to Company  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrestridgeLane1365WestStPaulMNMember
Buildings, Improvements & Equipment 3,608us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrestridgeLane1365WestStPaulMNMember
Cost Capitalized Subsequent to Acquisition 100snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrestridgeLane1365WestStPaulMNMember
Cost at the end of the period  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrestridgeLane1365WestStPaulMNMember
Buildings, Improvements & Equipment 3,708us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrestridgeLane1365WestStPaulMNMember
Total 4,108us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrestridgeLane1365WestStPaulMNMember
Accumulated Depreciation 1,379us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrestridgeLane1365WestStPaulMNMember
305 & 315 Thompson Avenue, West St. Paul, MN  
Initial Cost to Company  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ThompsonAvenue305And315WestStPaulMNMember
Buildings, Improvements & Equipment 2,506us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ThompsonAvenue305And315WestStPaulMNMember
Cost at the end of the period  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ThompsonAvenue305And315WestStPaulMNMember
Buildings, Improvements & Equipment 2,506us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ThompsonAvenue305And315WestStPaulMNMember
Total 2,906us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ThompsonAvenue305And315WestStPaulMNMember
Accumulated Depreciation 946us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ThompsonAvenue305And315WestStPaulMNMember
3828 College View Drive, Joplin (4), MO  
Real Estate And Accumulated Depreciation  
Encumbrances 5,625us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CollegeViewDrive3828JoplinMOMember
Initial Cost to Company  
Land 260us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CollegeViewDrive3828JoplinMOMember
Buildings, Improvements & Equipment 11,382us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CollegeViewDrive3828JoplinMOMember
Cost Capitalized Subsequent to Acquisition 142snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CollegeViewDrive3828JoplinMOMember
Cost at the end of the period  
Land 260us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CollegeViewDrive3828JoplinMOMember
Buildings, Improvements & Equipment 11,524us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CollegeViewDrive3828JoplinMOMember
Total 11,784us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CollegeViewDrive3828JoplinMOMember
Accumulated Depreciation 781us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CollegeViewDrive3828JoplinMOMember
1 Lincoln Parkway, Hattiesburg, MS  
Initial Cost to Company  
Land 1,269us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LincolnParkway1HattiesburgMSMember
Buildings, Improvements & Equipment 11,691us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LincolnParkway1HattiesburgMSMember
Cost Capitalized Subsequent to Acquisition 17snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LincolnParkway1HattiesburgMSMember
Cost at the end of the period  
Land 1,269us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LincolnParkway1HattiesburgMSMember
Buildings, Improvements & Equipment 11,708us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LincolnParkway1HattiesburgMSMember
Total 12,977us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LincolnParkway1HattiesburgMSMember
Accumulated Depreciation 512us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LincolnParkway1HattiesburgMSMember
1488 Belk Boulevard, Oxford, MS  
Initial Cost to Company  
Land 450us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BelkBoulevard1488OxfordMSMember
Buildings, Improvements & Equipment 5,791us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BelkBoulevard1488OxfordMSMember
Cost Capitalized Subsequent to Acquisition 304snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BelkBoulevard1488OxfordMSMember
Cost at the end of the period  
Land 450us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BelkBoulevard1488OxfordMSMember
Buildings, Improvements & Equipment 6,095us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BelkBoulevard1488OxfordMSMember
Total 6,545us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BelkBoulevard1488OxfordMSMember
Accumulated Depreciation 1,299us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BelkBoulevard1488OxfordMSMember
108 Clarington Drive, Southaven, MS  
Initial Cost to Company  
Land 450us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClaringtonDrive108SouthavenMSMember
Buildings, Improvements & Equipment 5,795us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClaringtonDrive108SouthavenMSMember
Cost Capitalized Subsequent to Acquisition 355snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClaringtonDrive108SouthavenMSMember
Cost at the end of the period  
Land 450us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClaringtonDrive108SouthavenMSMember
Buildings, Improvements & Equipment 6,150us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClaringtonDrive108SouthavenMSMember
Total 6,600us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClaringtonDrive108SouthavenMSMember
Accumulated Depreciation 1,312us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClaringtonDrive108SouthavenMSMember
112 + 118 Alamance Road, Burlington (4), NC  
Real Estate And Accumulated Depreciation  
Encumbrances 6,243us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AlamanceRoad112And118BurlingtonNCMember
Initial Cost to Company  
Land 575us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AlamanceRoad112And118BurlingtonNCMember
Buildings, Improvements & Equipment 9,697us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AlamanceRoad112And118BurlingtonNCMember
Cost Capitalized Subsequent to Acquisition 253snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AlamanceRoad112And118BurlingtonNCMember
Cost at the end of the period  
Land 575us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AlamanceRoad112And118BurlingtonNCMember
Buildings, Improvements & Equipment 9,950us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AlamanceRoad112And118BurlingtonNCMember
Total 10,525us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AlamanceRoad112And118BurlingtonNCMember
Accumulated Depreciation 974us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AlamanceRoad112And118BurlingtonNCMember
1050 Crescent Green Drive, Cary (4), NC  
Real Estate And Accumulated Depreciation  
Encumbrances 8,252us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrescentGreenDrive1050CaryNCMember
Initial Cost to Company  
Land 713us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrescentGreenDrive1050CaryNCMember
Buildings, Improvements & Equipment 4,628us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrescentGreenDrive1050CaryNCMember
Cost Capitalized Subsequent to Acquisition 1,952snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrescentGreenDrive1050CaryNCMember
Cost at the end of the period  
Land 713us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrescentGreenDrive1050CaryNCMember
Buildings, Improvements & Equipment 6,580us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrescentGreenDrive1050CaryNCMember
Total 7,293us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrescentGreenDrive1050CaryNCMember
Accumulated Depreciation 2,367us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrescentGreenDrive1050CaryNCMember
2220 & 2230 Farmington Drive, Chapel Hill, NC  
Initial Cost to Company  
Land 800us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FarmingtonDrive2220And2230ChapelHillNCMember
Buildings, Improvements & Equipment 6,414us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FarmingtonDrive2220And2230ChapelHillNCMember
Cost at the end of the period  
Land 800us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FarmingtonDrive2220And2230ChapelHillNCMember
Buildings, Improvements & Equipment 6,414us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FarmingtonDrive2220And2230ChapelHillNCMember
Total 7,214us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FarmingtonDrive2220And2230ChapelHillNCMember
Accumulated Depreciation 2,163us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FarmingtonDrive2220And2230ChapelHillNCMember
2101 Runnymede Lane, Charlotte, NC  
Initial Cost to Company  
Land 2,475us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RunnymedeLane2101CharlotteNCMember
Buildings, Improvements & Equipment 11,451us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RunnymedeLane2101CharlotteNCMember
Cost Capitalized Subsequent to Acquisition 437snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RunnymedeLane2101CharlotteNCMember
Cost at the end of the period  
Land 2,475us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RunnymedeLane2101CharlotteNCMember
Buildings, Improvements & Equipment 11,888us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RunnymedeLane2101CharlotteNCMember
Total 14,363us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RunnymedeLane2101CharlotteNCMember
Accumulated Depreciation 1,207us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RunnymedeLane2101CharlotteNCMember
5920 McChesney Drive, Charlotte, NC  
Initial Cost to Company  
Land 820us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McChesneyDrive5920CharlotteNCMember
Buildings, Improvements & Equipment 7,790us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McChesneyDrive5920CharlotteNCMember
Cost Capitalized Subsequent to Acquisition 483snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McChesneyDrive5920CharlotteNCMember
Cost at the end of the period  
Land 820us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McChesneyDrive5920CharlotteNCMember
Buildings, Improvements & Equipment 8,273us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McChesneyDrive5920CharlotteNCMember
Total 9,093us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McChesneyDrive5920CharlotteNCMember
Accumulated Depreciation 1,141us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McChesneyDrive5920CharlotteNCMember
6101 Clarke Creek Parkway, Charlotte, NC  
Initial Cost to Company  
Land 500us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClarkeCreekParkway6101CharlotteNCMember
Buildings, Improvements & Equipment 13,960us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClarkeCreekParkway6101CharlotteNCMember
Cost Capitalized Subsequent to Acquisition 36snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClarkeCreekParkway6101CharlotteNCMember
Cost at the end of the period  
Land 500us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClarkeCreekParkway6101CharlotteNCMember
Buildings, Improvements & Equipment 13,996us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClarkeCreekParkway6101CharlotteNCMember
Total 14,496us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClarkeCreekParkway6101CharlotteNCMember
Accumulated Depreciation 2,010us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClarkeCreekParkway6101CharlotteNCMember
1002 State Highway 54, Durham, NC  
Initial Cost to Company  
Land 595us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateHighway541002DurhamNCMember
Buildings, Improvements & Equipment 5,200us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateHighway541002DurhamNCMember
Cost Capitalized Subsequent to Acquisition 131snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateHighway541002DurhamNCMember
Cost at the end of the period  
Land 595us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateHighway541002DurhamNCMember
Buildings, Improvements & Equipment 5,331us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateHighway541002DurhamNCMember
Total 5,926us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateHighway541002DurhamNCMember
Accumulated Depreciation 520us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateHighway541002DurhamNCMember
1001 Phifer Road, Kings Mountain (4), NC  
Real Estate And Accumulated Depreciation  
Encumbrances 3,098us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PhiferRoad1001KingsMountainNCMember
Initial Cost to Company  
Land 655us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PhiferRoad1001KingsMountainNCMember
Buildings, Improvements & Equipment 8,283us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PhiferRoad1001KingsMountainNCMember
Cost Capitalized Subsequent to Acquisition 222snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PhiferRoad1001KingsMountainNCMember
Cost at the end of the period  
Land 655us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PhiferRoad1001KingsMountainNCMember
Buildings, Improvements & Equipment 8,505us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PhiferRoad1001KingsMountainNCMember
Total 9,160us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PhiferRoad1001KingsMountainNCMember
Accumulated Depreciation 866us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PhiferRoad1001KingsMountainNCMember
128 Brawley School, Mooresville (4), NC  
Real Estate And Accumulated Depreciation  
Encumbrances 4,494us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrawleySchool128Mooresville-4NCMember
Initial Cost to Company  
Land 595us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrawleySchool128Mooresville-4NCMember
Buildings, Improvements & Equipment 7,305us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrawleySchool128Mooresville-4NCMember
Cost Capitalized Subsequent to Acquisition 343snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrawleySchool128Mooresville-4NCMember
Cost at the end of the period  
Land 595us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrawleySchool128Mooresville-4NCMember
Buildings, Improvements & Equipment 7,648us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrawleySchool128Mooresville-4NCMember
Total 8,243us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrawleySchool128Mooresville-4NCMember
Accumulated Depreciation 726us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrawleySchool128Mooresville-4NCMember
1309 , 1321 + 1325 McCarthy Boulevard, New Bern (4), NC  
Real Estate And Accumulated Depreciation  
Encumbrances 4,914us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McCarthyBoulevard1309And1321And1325NewBernNCMember
Initial Cost to Company  
Land 1,245us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McCarthyBoulevard1309And1321And1325NewBernNCMember
Buildings, Improvements & Equipment 20,898us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McCarthyBoulevard1309And1321And1325NewBernNCMember
Cost Capitalized Subsequent to Acquisition 381snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McCarthyBoulevard1309And1321And1325NewBernNCMember
Cost at the end of the period  
Land 1,245us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McCarthyBoulevard1309And1321And1325NewBernNCMember
Buildings, Improvements & Equipment 21,279us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McCarthyBoulevard1309And1321And1325NewBernNCMember
Total 22,524us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McCarthyBoulevard1309And1321And1325NewBernNCMember
Accumulated Depreciation 2,013us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McCarthyBoulevard1309And1321And1325NewBernNCMember
13150 Dorman Road, Pineville, NC  
Initial Cost to Company  
Land 550us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DormanRoad13150PinevilleNCMember
Buildings, Improvements & Equipment 7,570us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DormanRoad13150PinevilleNCMember
Cost Capitalized Subsequent to Acquisition 288snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DormanRoad13150PinevilleNCMember
Cost at the end of the period  
Land 550us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DormanRoad13150PinevilleNCMember
Buildings, Improvements & Equipment 7,858us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DormanRoad13150PinevilleNCMember
Total 8,408us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DormanRoad13150PinevilleNCMember
Accumulated Depreciation 1,104us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DormanRoad13150PinevilleNCMember
13180 Dorman Road, Pineville, NC  
Initial Cost to Company  
Land 630us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DormanRoad13180PinevilleNCMember
Buildings, Improvements & Equipment 15,230us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DormanRoad13180PinevilleNCMember
Cost Capitalized Subsequent to Acquisition 7snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DormanRoad13180PinevilleNCMember
Cost at the end of the period  
Land 630us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DormanRoad13180PinevilleNCMember
Buildings, Improvements & Equipment 15,237us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DormanRoad13180PinevilleNCMember
Total 15,867us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DormanRoad13180PinevilleNCMember
Accumulated Depreciation 2,187us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DormanRoad13180PinevilleNCMember
1730 Parkwood Boulevard West, Wilson (4), NC  
Real Estate And Accumulated Depreciation  
Encumbrances 2,728us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkwoodBoulevardWest1730WilsonNCMember
Initial Cost to Company  
Land 610us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkwoodBoulevardWest1730WilsonNCMember
Buildings, Improvements & Equipment 14,787us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkwoodBoulevardWest1730WilsonNCMember
Cost Capitalized Subsequent to Acquisition 63snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkwoodBoulevardWest1730WilsonNCMember
Cost at the end of the period  
Land 610us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkwoodBoulevardWest1730WilsonNCMember
Buildings, Improvements & Equipment 14,850us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkwoodBoulevardWest1730WilsonNCMember
Total 15,460us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkwoodBoulevardWest1730WilsonNCMember
Accumulated Depreciation 1,469us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkwoodBoulevardWest1730WilsonNCMember
1700 Furnace Street, Ashland, NE  
Initial Cost to Company  
Land 28us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FurnaceStreet1700AshlandNEMember
Buildings, Improvements & Equipment 1,823us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FurnaceStreet1700AshlandNEMember
Cost Capitalized Subsequent to Acquisition 1,281snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FurnaceStreet1700AshlandNEMember
Cost at the end of the period  
Land 28us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FurnaceStreet1700AshlandNEMember
Buildings, Improvements & Equipment 3,104us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FurnaceStreet1700AshlandNEMember
Total 3,132us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FurnaceStreet1700AshlandNEMember
Accumulated Depreciation 1,362us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FurnaceStreet1700AshlandNEMember
414 North Wilson Street, Blue Hill , NE  
Initial Cost to Company  
Land 56us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthWilsonStreet414BlueHillNEMember
Buildings, Improvements & Equipment 1,064us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthWilsonStreet414BlueHillNEMember
Cost Capitalized Subsequent to Acquisition 807snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthWilsonStreet414BlueHillNEMember
Cost at the end of the period  
Land 56us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthWilsonStreet414BlueHillNEMember
Buildings, Improvements & Equipment 1,871us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthWilsonStreet414BlueHillNEMember
Total 1,927us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthWilsonStreet414BlueHillNEMember
Accumulated Depreciation 803us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthWilsonStreet414BlueHillNEMember
2720 South 17th Ave, Central City, NE  
Initial Cost to Company  
Land 21us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South17thAve2720CentralCityNEMember
Buildings, Improvements & Equipment 919us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South17thAve2720CentralCityNEMember
Cost Capitalized Subsequent to Acquisition 650snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South17thAve2720CentralCityNEMember
Cost at the end of the period  
Land 21us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South17thAve2720CentralCityNEMember
Buildings, Improvements & Equipment 1,569us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South17thAve2720CentralCityNEMember
Total 1,590us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South17thAve2720CentralCityNEMember
Accumulated Depreciation 769us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South17thAve2720CentralCityNEMember
1112 15th Street, Columbus, NE  
Initial Cost to Company  
Land 88us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Street15th1112ColumbusNEMember
Buildings, Improvements & Equipment 561us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Street15th1112ColumbusNEMember
Cost Capitalized Subsequent to Acquisition 462snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Street15th1112ColumbusNEMember
Cost at the end of the period  
Land 89us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Street15th1112ColumbusNEMember
Buildings, Improvements & Equipment 1,022us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Street15th1112ColumbusNEMember
Total 1,111us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Street15th1112ColumbusNEMember
Accumulated Depreciation 512us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Street15th1112ColumbusNEMember
800 Stoeger Drive, Grand Island, NE  
Initial Cost to Company  
Land 119us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StoegerDrive800GrandIslandNEMember
Buildings, Improvements & Equipment 1,446us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StoegerDrive800GrandIslandNEMember
Cost Capitalized Subsequent to Acquisition 1,404snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StoegerDrive800GrandIslandNEMember
Cost at the end of the period  
Land 119us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StoegerDrive800GrandIslandNEMember
Buildings, Improvements & Equipment 2,850us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StoegerDrive800GrandIslandNEMember
Total 2,969us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StoegerDrive800GrandIslandNEMember
Accumulated Depreciation 1,369us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StoegerDrive800GrandIslandNEMember
700 South Highway 6, Gretna, NE  
Initial Cost to Company  
Land 237us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthHighway6700GretnaNEMember
Buildings, Improvements & Equipment 673us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthHighway6700GretnaNEMember
Cost Capitalized Subsequent to Acquisition 897snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthHighway6700GretnaNEMember
Cost at the end of the period  
Land 237us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthHighway6700GretnaNEMember
Buildings, Improvements & Equipment 1,570us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthHighway6700GretnaNEMember
Total 1,807us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthHighway6700GretnaNEMember
Accumulated Depreciation 691us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SouthHighway6700GretnaNEMember
1100 West First Street, Milford, NE  
Initial Cost to Company  
Land 24us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestFirstStreet1100MilfordNEMember
Buildings, Improvements & Equipment 880us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestFirstStreet1100MilfordNEMember
Cost Capitalized Subsequent to Acquisition 648snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestFirstStreet1100MilfordNEMember
Cost at the end of the period  
Land 24us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestFirstStreet1100MilfordNEMember
Buildings, Improvements & Equipment 1,528us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestFirstStreet1100MilfordNEMember
Total 1,552us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestFirstStreet1100MilfordNEMember
Accumulated Depreciation 741us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestFirstStreet1100MilfordNEMember
510 Centennial Circle , North Platte, NE  
Initial Cost to Company  
Land 370us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentennialCircle510NorthPlatteNEMember
Buildings, Improvements & Equipment 8,968us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentennialCircle510NorthPlatteNEMember
Cost Capitalized Subsequent to Acquisition 619snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentennialCircle510NorthPlatteNEMember
Cost at the end of the period  
Land 370us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentennialCircle510NorthPlatteNEMember
Buildings, Improvements & Equipment 9,587us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentennialCircle510NorthPlatteNEMember
Total 9,957us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentennialCircle510NorthPlatteNEMember
Accumulated Depreciation 1,610us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentennialCircle510NorthPlatteNEMember
17007 Elm Plaza, Omaha, NE  
Initial Cost to Company  
Land 4,680us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmPlaza17007OmahaNEMember
Buildings, Improvements & Equipment 22,022us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmPlaza17007OmahaNEMember
Cost at the end of the period  
Land 4,680us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmPlaza17007OmahaNEMember
Buildings, Improvements & Equipment 22,022us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmPlaza17007OmahaNEMember
Total 26,702us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmPlaza17007OmahaNEMember
Accumulated Depreciation 3,510us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElmPlaza17007OmahaNEMember
3030 South 80th Street, Omaha, NE  
Initial Cost to Company  
Land 650us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South80thStreet3030OmahaNEMember
Buildings, Improvements & Equipment 5,850us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South80thStreet3030OmahaNEMember
Cost Capitalized Subsequent to Acquisition 443snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South80thStreet3030OmahaNEMember
Cost at the end of the period  
Land 650us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South80thStreet3030OmahaNEMember
Buildings, Improvements & Equipment 6,293us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South80thStreet3030OmahaNEMember
Total 6,943us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South80thStreet3030OmahaNEMember
Accumulated Depreciation 1,673us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South80thStreet3030OmahaNEMember
333 Maple, Sutherland, NE  
Initial Cost to Company  
Land 19us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Maple333SutherlandNEMember
Buildings, Improvements & Equipment 1,251us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Maple333SutherlandNEMember
Cost Capitalized Subsequent to Acquisition 487snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Maple333SutherlandNEMember
Cost at the end of the period  
Land 19us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Maple333SutherlandNEMember
Buildings, Improvements & Equipment 1,738us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Maple333SutherlandNEMember
Total 1,757us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Maple333SutherlandNEMember
Accumulated Depreciation 752us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Maple333SutherlandNEMember
1350 Centenial Ave, Utica, NE  
Initial Cost to Company  
Land 21us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentenialAve1350UticaNEMember
Buildings, Improvements & Equipment 569us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentenialAve1350UticaNEMember
Cost Capitalized Subsequent to Acquisition 447snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentenialAve1350UticaNEMember
Cost at the end of the period  
Land 21us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentenialAve1350UticaNEMember
Buildings, Improvements & Equipment 1,016us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentenialAve1350UticaNEMember
Total 1,037us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentenialAve1350UticaNEMember
Accumulated Depreciation 444us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentenialAve1350UticaNEMember
11041 North 137th Street, Waverly, NE  
Initial Cost to Company  
Land 529us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North137thStreet11041WaverlyNEMember
Buildings, Improvements & Equipment 686us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North137thStreet11041WaverlyNEMember
Cost Capitalized Subsequent to Acquisition 609snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North137thStreet11041WaverlyNEMember
Cost at the end of the period  
Land 529us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North137thStreet11041WaverlyNEMember
Buildings, Improvements & Equipment 1,295us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North137thStreet11041WaverlyNEMember
Total 1,824us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North137thStreet11041WaverlyNEMember
Accumulated Depreciation 696us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North137thStreet11041WaverlyNEMember
490 Cooper Landing Road, Cherry Hill, NJ  
Initial Cost to Company  
Land 1,001us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CooperLandingRoad490CherryHillNJMember
Buildings, Improvements & Equipment 8,175us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CooperLandingRoad490CherryHillNJMember
Cost Capitalized Subsequent to Acquisition 1,836snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CooperLandingRoad490CherryHillNJMember
Cost at the end of the period  
Land 1,001us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CooperLandingRoad490CherryHillNJMember
Buildings, Improvements & Equipment 10,011us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CooperLandingRoad490CherryHillNJMember
Total 11,012us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CooperLandingRoad490CherryHillNJMember
Accumulated Depreciation 2,592us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CooperLandingRoad490CherryHillNJMember
1400 Route 70, Lakewood (6), NJ  
Initial Cost to Company  
Land 4,885us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Route701400LakewoodNJMember
Buildings, Improvements & Equipment 28,803us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Route701400LakewoodNJMember
Cost Capitalized Subsequent to Acquisition 2,562snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Route701400LakewoodNJMember
Cost at the end of the period  
Land 4,885us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Route701400LakewoodNJMember
Buildings, Improvements & Equipment 31,365us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Route701400LakewoodNJMember
Total 36,250us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Route701400LakewoodNJMember
Accumulated Depreciation 11,421us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Route701400LakewoodNJMember
2 Hillside Drive, Mt. Arlington, NJ  
Initial Cost to Company  
Land 1,375us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HillsideDrive2MtArlingtonNJMember
Buildings, Improvements & Equipment 11,232us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HillsideDrive2MtArlingtonNJMember
Cost Capitalized Subsequent to Acquisition 757snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HillsideDrive2MtArlingtonNJMember
Cost at the end of the period  
Land 1,375us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HillsideDrive2MtArlingtonNJMember
Buildings, Improvements & Equipment 11,989us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HillsideDrive2MtArlingtonNJMember
Total 13,364us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HillsideDrive2MtArlingtonNJMember
Accumulated Depreciation 3,532us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HillsideDrive2MtArlingtonNJMember
655 Pomander Walk, Teaneck (4), NJ  
Real Estate And Accumulated Depreciation  
Encumbrances 31,528us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PomanderWalk655TeaneckNJMember
Initial Cost to Company  
Land 4,950us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PomanderWalk655TeaneckNJMember
Buildings, Improvements & Equipment 44,550us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PomanderWalk655TeaneckNJMember
Cost Capitalized Subsequent to Acquisition 1,728snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PomanderWalk655TeaneckNJMember
Cost at the end of the period  
Land 4,950us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PomanderWalk655TeaneckNJMember
Buildings, Improvements & Equipment 46,278us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PomanderWalk655TeaneckNJMember
Total 51,228us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PomanderWalk655TeaneckNJMember
Accumulated Depreciation 4,193us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PomanderWalk655TeaneckNJMember
10500 Academy Road NE, Albuquerque (4), NM  
Real Estate And Accumulated Depreciation  
Encumbrances 25,991us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AcademyRoadNE10500AlbuquerqueNMMember
Initial Cost to Company  
Land 3,828us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AcademyRoadNE10500AlbuquerqueNMMember
Buildings, Improvements & Equipment 22,572us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AcademyRoadNE10500AlbuquerqueNMMember
Cost Capitalized Subsequent to Acquisition 5,325snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AcademyRoadNE10500AlbuquerqueNMMember
Cost at the end of the period  
Land 3,828us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AcademyRoadNE10500AlbuquerqueNMMember
Buildings, Improvements & Equipment 27,897us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AcademyRoadNE10500AlbuquerqueNMMember
Total 31,725us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AcademyRoadNE10500AlbuquerqueNMMember
Accumulated Depreciation 9,520us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AcademyRoadNE10500AlbuquerqueNMMember
4100 Prospect Avenue NE, Albuquerque, NM  
Initial Cost to Company  
Land 540us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProspectAvenueNE4100AlbuquerqueNMMember
Buildings, Improvements & Equipment 10,105us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProspectAvenueNE4100AlbuquerqueNMMember
Cost Capitalized Subsequent to Acquisition 8snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProspectAvenueNE4100AlbuquerqueNMMember
Cost at the end of the period  
Land 540us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProspectAvenueNE4100AlbuquerqueNMMember
Buildings, Improvements & Equipment 10,113us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProspectAvenueNE4100AlbuquerqueNMMember
Total 10,653us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProspectAvenueNE4100AlbuquerqueNMMember
Accumulated Depreciation 1,822us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ProspectAvenueNE4100AlbuquerqueNMMember
4300 Landau Street NE, Albuquerque, NM  
Initial Cost to Company  
Land 1,060us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LandauStreetNE4300AlbuquerqueNMMember
Buildings, Improvements & Equipment 9,875us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LandauStreetNE4300AlbuquerqueNMMember
Cost Capitalized Subsequent to Acquisition 8snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LandauStreetNE4300AlbuquerqueNMMember
Cost at the end of the period  
Land 1,060us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LandauStreetNE4300AlbuquerqueNMMember
Buildings, Improvements & Equipment 9,883us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LandauStreetNE4300AlbuquerqueNMMember
Total 10,943us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LandauStreetNE4300AlbuquerqueNMMember
Accumulated Depreciation 1,781us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LandauStreetNE4300AlbuquerqueNMMember
4411 The 25 Way, Albuquerque, NM  
Initial Cost to Company  
Land 3,480us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_The25Way4411AlbuquerqueNMMember
Buildings, Improvements & Equipment 25,245us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_The25Way4411AlbuquerqueNMMember
Cost Capitalized Subsequent to Acquisition 4,120snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_The25Way4411AlbuquerqueNMMember
Cost at the end of the period  
Land 3,593us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_The25Way4411AlbuquerqueNMMember
Buildings, Improvements & Equipment 29,252us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_The25Way4411AlbuquerqueNMMember
Total 32,845us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_The25Way4411AlbuquerqueNMMember
Accumulated Depreciation 2,961us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_The25Way4411AlbuquerqueNMMember
4420 The 25 Way, Albuquerque, NM  
Initial Cost to Company  
Land 1,430us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_The25Way4420AlbuquerqueNMMember
Buildings, Improvements & Equipment 2,609us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_The25Way4420AlbuquerqueNMMember
Cost Capitalized Subsequent to Acquisition 65snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_The25Way4420AlbuquerqueNMMember
Cost at the end of the period  
Land 1,476us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_The25Way4420AlbuquerqueNMMember
Buildings, Improvements & Equipment 2,628us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_The25Way4420AlbuquerqueNMMember
Total 4,104us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_The25Way4420AlbuquerqueNMMember
Accumulated Depreciation 268us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_The25Way4420AlbuquerqueNMMember
9190 Coors Boulevard NW, Albuquerque, NM  
Initial Cost to Company  
Land 1,660us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CoorsBoulevardNW9190AlbuquerqueNMMember
Buildings, Improvements & Equipment 9,173us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CoorsBoulevardNW9190AlbuquerqueNMMember
Cost Capitalized Subsequent to Acquisition 8snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CoorsBoulevardNW9190AlbuquerqueNMMember
Cost at the end of the period  
Land 1,660us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CoorsBoulevardNW9190AlbuquerqueNMMember
Buildings, Improvements & Equipment 9,181us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CoorsBoulevardNW9190AlbuquerqueNMMember
Total 10,841us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CoorsBoulevardNW9190AlbuquerqueNMMember
Accumulated Depreciation 1,654us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CoorsBoulevardNW9190AlbuquerqueNMMember
3201 Plumas Street, Reno, NV  
Initial Cost to Company  
Land 2,420us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PlumasStreet3201RenoNVMember
Buildings, Improvements & Equipment 49,580us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PlumasStreet3201RenoNVMember
Cost Capitalized Subsequent to Acquisition 5,439snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PlumasStreet3201RenoNVMember
Cost at the end of the period  
Land 2,420us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PlumasStreet3201RenoNVMember
Buildings, Improvements & Equipment 55,019us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PlumasStreet3201RenoNVMember
Total 57,439us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PlumasStreet3201RenoNVMember
Accumulated Depreciation 4,218us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PlumasStreet3201RenoNVMember
6300 Eighth Ave, Brooklyn, NY  
Initial Cost to Company  
Land 3,870us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EighthAve6300BrooklynNYMember
Buildings, Improvements & Equipment 8,545us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EighthAve6300BrooklynNYMember
Cost Capitalized Subsequent to Acquisition 6snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EighthAve6300BrooklynNYMember
Cost at the end of the period  
Land 3,870us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EighthAve6300BrooklynNYMember
Buildings, Improvements & Equipment 8,551us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EighthAve6300BrooklynNYMember
Total 12,421us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EighthAve6300BrooklynNYMember
Accumulated Depreciation 1,363us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EighthAve6300BrooklynNYMember
5823 Widewaters Parkway, Dewitt, NY  
Initial Cost to Company  
Land 600us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WidewatersParkway5823DewittNYMember
Buildings, Improvements & Equipment 5,004us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WidewatersParkway5823DewittNYMember
Cost Capitalized Subsequent to Acquisition 797snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WidewatersParkway5823DewittNYMember
Cost at the end of the period  
Land 600us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WidewatersParkway5823DewittNYMember
Buildings, Improvements & Equipment 5,801us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WidewatersParkway5823DewittNYMember
Total 6,401us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WidewatersParkway5823DewittNYMember
Accumulated Depreciation 429us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WidewatersParkway5823DewittNYMember
4939 Brittonfield Parkway, East Syracuse, NY  
Initial Cost to Company  
Land 720us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrittonfieldParkway4939EastSyracuseNYMember
Buildings, Improvements & Equipment 17,084us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrittonfieldParkway4939EastSyracuseNYMember
Cost Capitalized Subsequent to Acquisition 290snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrittonfieldParkway4939EastSyracuseNYMember
Cost at the end of the period  
Land 720us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrittonfieldParkway4939EastSyracuseNYMember
Buildings, Improvements & Equipment 17,374us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrittonfieldParkway4939EastSyracuseNYMember
Total 18,094us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrittonfieldParkway4939EastSyracuseNYMember
Accumulated Depreciation 2,711us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrittonfieldParkway4939EastSyracuseNYMember
5008 Brittonfield Parkway, East Syracuse (4), NY  
Real Estate And Accumulated Depreciation  
Encumbrances 4,068us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrittonfieldParkway5008EastSyracuseNYMember
Initial Cost to Company  
Land 420us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrittonfieldParkway5008EastSyracuseNYMember
Buildings, Improvements & Equipment 18,407us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrittonfieldParkway5008EastSyracuseNYMember
Cost Capitalized Subsequent to Acquisition 289snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrittonfieldParkway5008EastSyracuseNYMember
Cost at the end of the period  
Land 458us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrittonfieldParkway5008EastSyracuseNYMember
Buildings, Improvements & Equipment 18,658us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrittonfieldParkway5008EastSyracuseNYMember
Total 19,116us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrittonfieldParkway5008EastSyracuseNYMember
Accumulated Depreciation 2,979us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BrittonfieldParkway5008EastSyracuseNYMember
200 Old County Road, Mineola, NY  
Initial Cost to Company  
Land 4,920us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCountyRoad200MineolaNYMember
Buildings, Improvements & Equipment 24,056us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCountyRoad200MineolaNYMember
Cost Capitalized Subsequent to Acquisition 2,177snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCountyRoad200MineolaNYMember
Cost at the end of the period  
Land 4,920us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCountyRoad200MineolaNYMember
Buildings, Improvements & Equipment 26,233us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCountyRoad200MineolaNYMember
Total 31,153us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCountyRoad200MineolaNYMember
Accumulated Depreciation 2,135us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldCountyRoad200MineolaNYMember
15 North Broadway, White Plains, NY  
Initial Cost to Company  
Land 4,900us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthBroadway15WhitePlainsNYMember
Buildings, Improvements & Equipment 13,594us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthBroadway15WhitePlainsNYMember
Cost at the end of the period  
Land 4,900us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthBroadway15WhitePlainsNYMember
Buildings, Improvements & Equipment 13,594us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthBroadway15WhitePlainsNYMember
Total 18,494us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthBroadway15WhitePlainsNYMember
Accumulated Depreciation 2,026us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthBroadway15WhitePlainsNYMember
537 Riverdale Avenue, Yonkers (4), NY  
Real Estate And Accumulated Depreciation  
Encumbrances 29,362us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiverdaleAvenue537YonkersNYMember
Initial Cost to Company  
Land 8,460us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiverdaleAvenue537YonkersNYMember
Buildings, Improvements & Equipment 90,561us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiverdaleAvenue537YonkersNYMember
Cost Capitalized Subsequent to Acquisition 1,273snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiverdaleAvenue537YonkersNYMember
Cost at the end of the period  
Land 8,460us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiverdaleAvenue537YonkersNYMember
Buildings, Improvements & Equipment 91,834us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiverdaleAvenue537YonkersNYMember
Total 100,294us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiverdaleAvenue537YonkersNYMember
Accumulated Depreciation 6,049us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiverdaleAvenue537YonkersNYMember
4590 and 4625 Knightsbridge Boulevard, Columbus (4), OH  
Real Estate And Accumulated Depreciation  
Encumbrances 18,104us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsbridgeBoulevard4590And4625ColumbusOHMember
Initial Cost to Company  
Land 3,623us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsbridgeBoulevard4590And4625ColumbusOHMember
Buildings, Improvements & Equipment 27,778us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsbridgeBoulevard4590And4625ColumbusOHMember
Cost Capitalized Subsequent to Acquisition 7,164snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsbridgeBoulevard4590And4625ColumbusOHMember
Cost at the end of the period  
Land 3,623us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsbridgeBoulevard4590And4625ColumbusOHMember
Buildings, Improvements & Equipment 34,942us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsbridgeBoulevard4590And4625ColumbusOHMember
Total 38,565us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsbridgeBoulevard4590And4625ColumbusOHMember
Accumulated Depreciation 12,624us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsbridgeBoulevard4590And4625ColumbusOHMember
3929 Hoover Road, Grove City, OH  
Initial Cost to Company  
Land 332us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HooverRoad3929GroveCityOHMember
Buildings, Improvements & Equipment 3,081us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HooverRoad3929GroveCityOHMember
Cost Capitalized Subsequent to Acquisition 791snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HooverRoad3929GroveCityOHMember
Cost at the end of the period  
Land 332us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HooverRoad3929GroveCityOHMember
Buildings, Improvements & Equipment 3,872us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HooverRoad3929GroveCityOHMember
Total 4,204us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HooverRoad3929GroveCityOHMember
Accumulated Depreciation 1,871us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HooverRoad3929GroveCityOHMember
5260 Naiman Parkway, Solon, OH  
Initial Cost to Company  
Land 450us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NaimanParkway5260SolonOHMember
Buildings, Improvements & Equipment 2,305us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NaimanParkway5260SolonOHMember
Cost Capitalized Subsequent to Acquisition 330snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NaimanParkway5260SolonOHMember
Cost at the end of the period  
Land 599us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NaimanParkway5260SolonOHMember
Buildings, Improvements & Equipment 2,486us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NaimanParkway5260SolonOHMember
Total 3,085us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NaimanParkway5260SolonOHMember
Accumulated Depreciation 289us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NaimanParkway5260SolonOHMember
5370 Naiman Parkway, Solon, OH  
Initial Cost to Company  
Land 550us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NaimanParkway5370SolonOHMember
Buildings, Improvements & Equipment 2,147us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NaimanParkway5370SolonOHMember
Cost Capitalized Subsequent to Acquisition 54snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NaimanParkway5370SolonOHMember
Cost at the end of the period  
Land 550us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NaimanParkway5370SolonOHMember
Buildings, Improvements & Equipment 2,201us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NaimanParkway5370SolonOHMember
Total 2,751us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NaimanParkway5370SolonOHMember
Accumulated Depreciation 177us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NaimanParkway5370SolonOHMember
200 N. Bryant Ave., Edmond, OK  
Initial Cost to Company  
Land 430us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NBryantAve200EdmondOKMember
Buildings, Improvements & Equipment 2,955us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NBryantAve200EdmondOKMember
Cost at the end of the period  
Land 430us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NBryantAve200EdmondOKMember
Buildings, Improvements & Equipment 2,955us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NBryantAve200EdmondOKMember
Total 3,385us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NBryantAve200EdmondOKMember
Accumulated Depreciation 394us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NBryantAve200EdmondOKMember
600 National Ave, Midwest City, OK  
Initial Cost to Company  
Land 410us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NationalAve600MidwestCityOKMember
Buildings, Improvements & Equipment 2,970us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NationalAve600MidwestCityOKMember
Cost at the end of the period  
Land 410us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NationalAve600MidwestCityOKMember
Buildings, Improvements & Equipment 2,970us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NationalAve600MidwestCityOKMember
Total 3,380us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NationalAve600MidwestCityOKMember
Accumulated Depreciation 396us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NationalAve600MidwestCityOKMember
701 Northeast 10th Street, Oklahoma City, OK  
Initial Cost to Company  
Land 500us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Northeast10thStreet701OklahomaCityOKMember
Buildings, Improvements & Equipment 19,046us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Northeast10thStreet701OklahomaCityOKMember
Cost at the end of the period  
Land 500us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Northeast10thStreet701OklahomaCityOKMember
Buildings, Improvements & Equipment 19,046us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Northeast10thStreet701OklahomaCityOKMember
Total 19,546us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Northeast10thStreet701OklahomaCityOKMember
Accumulated Depreciation 2,540us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Northeast10thStreet701OklahomaCityOKMember
8315 S. Walker Ave., Oklahoma City, OK  
Initial Cost to Company  
Land 480us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SWalkerAve8315OklahomaCityOKMember
Buildings, Improvements & Equipment 1,546us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SWalkerAve8315OklahomaCityOKMember
Cost at the end of the period  
Land 480us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SWalkerAve8315OklahomaCityOKMember
Buildings, Improvements & Equipment 1,546us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SWalkerAve8315OklahomaCityOKMember
Total 2,026us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SWalkerAve8315OklahomaCityOKMember
Accumulated Depreciation 206us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SWalkerAve8315OklahomaCityOKMember
71 Darlington Road, Beaver Falls, PA  
Initial Cost to Company  
Land 1,500us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DarlingtonRoad71BeaverFallsPAMember
Buildings, Improvements & Equipment 13,500us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DarlingtonRoad71BeaverFallsPAMember
Cost Capitalized Subsequent to Acquisition 444snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DarlingtonRoad71BeaverFallsPAMember
Cost at the end of the period  
Land 1,500us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DarlingtonRoad71BeaverFallsPAMember
Buildings, Improvements & Equipment 13,944us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DarlingtonRoad71BeaverFallsPAMember
Total 15,444us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DarlingtonRoad71BeaverFallsPAMember
Accumulated Depreciation 3,651us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DarlingtonRoad71BeaverFallsPAMember
200 Hill Church-Houston RD., Rt. 519 S., Canonsburg, PA  
Initial Cost to Company  
Land 1,518us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HillChurchHoustonRDRt519S200CanonsburgPAMember
Buildings, Improvements & Equipment 13,493us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HillChurchHoustonRDRt519S200CanonsburgPAMember
Cost Capitalized Subsequent to Acquisition 587snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HillChurchHoustonRDRt519S200CanonsburgPAMember
Cost at the end of the period  
Land 1,518us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HillChurchHoustonRDRt519S200CanonsburgPAMember
Buildings, Improvements & Equipment 14,080us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HillChurchHoustonRDRt519S200CanonsburgPAMember
Total 15,598us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HillChurchHoustonRDRt519S200CanonsburgPAMember
Accumulated Depreciation 10,645us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HillChurchHoustonRDRt519S200CanonsburgPAMember
950 Morgan Highway, Clarks Summit, PA  
Initial Cost to Company  
Land 1,001us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MorganHighway950ClarksSummitPAMember
Buildings, Improvements & Equipment 8,233us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MorganHighway950ClarksSummitPAMember
Cost Capitalized Subsequent to Acquisition 318snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MorganHighway950ClarksSummitPAMember
Cost at the end of the period  
Land 1,001us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MorganHighway950ClarksSummitPAMember
Buildings, Improvements & Equipment 8,551us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MorganHighway950ClarksSummitPAMember
Total 9,552us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MorganHighway950ClarksSummitPAMember
Accumulated Depreciation 2,534us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MorganHighway950ClarksSummitPAMember
145 Broadlawn Drive, Elizabeth, PA  
Initial Cost to Company  
Land 696us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BroadlawnDrive145ElizabethPAMember
Buildings, Improvements & Equipment 6,304us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BroadlawnDrive145ElizabethPAMember
Cost Capitalized Subsequent to Acquisition 690snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BroadlawnDrive145ElizabethPAMember
Cost at the end of the period  
Land 696us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BroadlawnDrive145ElizabethPAMember
Buildings, Improvements & Equipment 6,994us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BroadlawnDrive145ElizabethPAMember
Total 7,690us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BroadlawnDrive145ElizabethPAMember
Accumulated Depreciation 1,856us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BroadlawnDrive145ElizabethPAMember
600 N. Pottstown Pike, Exton, PA  
Initial Cost to Company  
Land 1,001us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPottstownPike600ExtonPAMember
Buildings, Improvements & Equipment 8,233us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPottstownPike600ExtonPAMember
Cost Capitalized Subsequent to Acquisition 1,038snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPottstownPike600ExtonPAMember
Cost at the end of the period  
Land 1,001us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPottstownPike600ExtonPAMember
Buildings, Improvements & Equipment 9,271us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPottstownPike600ExtonPAMember
Total 10,272us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPottstownPike600ExtonPAMember
Accumulated Depreciation 2,656us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPottstownPike600ExtonPAMember
475 Virginia Drive, Fort Washington, PA  
Initial Cost to Company  
Land 1,010us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VirginiaDrive475FortWashingtonPAMember
Buildings, Improvements & Equipment 4,837us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VirginiaDrive475FortWashingtonPAMember
Cost Capitalized Subsequent to Acquisition 104snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VirginiaDrive475FortWashingtonPAMember
Cost at the end of the period  
Land 1,010us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VirginiaDrive475FortWashingtonPAMember
Buildings, Improvements & Equipment 4,941us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VirginiaDrive475FortWashingtonPAMember
Total 5,951us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VirginiaDrive475FortWashingtonPAMember
Accumulated Depreciation 399us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VirginiaDrive475FortWashingtonPAMember
525 Virginia Drive, Fort Washington, PA  
Initial Cost to Company  
Land 3,100us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VirginiaDrive525FortWashingtonPAMember
Buildings, Improvements & Equipment 6,775us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VirginiaDrive525FortWashingtonPAMember
Cost Capitalized Subsequent to Acquisition 0snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VirginiaDrive525FortWashingtonPAMember
Impairment (9,222)snh_RealEstateAndAccumulatedDepreciationCarryingAmountOfImpairment
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VirginiaDrive525FortWashingtonPAMember
Cost at the end of the period  
Land 653us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VirginiaDrive525FortWashingtonPAMember
Total 653us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_VirginiaDrive525FortWashingtonPAMember
242 Baltimore Pike, Glen Mills, PA  
Initial Cost to Company  
Land 1,001us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BaltimorePike242GlenMillsPAMember
Buildings, Improvements & Equipment 8,233us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BaltimorePike242GlenMillsPAMember
Cost Capitalized Subsequent to Acquisition 484snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BaltimorePike242GlenMillsPAMember
Cost at the end of the period  
Land 1,001us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BaltimorePike242GlenMillsPAMember
Buildings, Improvements & Equipment 8,717us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BaltimorePike242GlenMillsPAMember
Total 9,718us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BaltimorePike242GlenMillsPAMember
Accumulated Depreciation 2,651us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BaltimorePike242GlenMillsPAMember
723 Dresher Road, Horsham, PA  
Initial Cost to Company  
Land 1,010us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DresherRoad723HorshamPAMember
Buildings, Improvements & Equipment 4,456us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DresherRoad723HorshamPAMember
Cost Capitalized Subsequent to Acquisition 431snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DresherRoad723HorshamPAMember
Cost at the end of the period  
Land 1,010us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DresherRoad723HorshamPAMember
Buildings, Improvements & Equipment 4,887us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DresherRoad723HorshamPAMember
Total 5,897us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DresherRoad723HorshamPAMember
Accumulated Depreciation 585us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DresherRoad723HorshamPAMember
210 Mall Boulevard, King of Prussia, PA  
Initial Cost to Company  
Land 1,540us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MallBoulevard210KingofPrussiaPAMember
Buildings, Improvements & Equipment 4,743us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MallBoulevard210KingofPrussiaPAMember
Cost Capitalized Subsequent to Acquisition (11)snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MallBoulevard210KingofPrussiaPAMember
Cost at the end of the period  
Land 1,540us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MallBoulevard210KingofPrussiaPAMember
Buildings, Improvements & Equipment 4,732us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MallBoulevard210KingofPrussiaPAMember
Total 6,272us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MallBoulevard210KingofPrussiaPAMember
Accumulated Depreciation 755us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MallBoulevard210KingofPrussiaPAMember
216 Mall Boulevard, King of Prussia, PA  
Initial Cost to Company  
Land 880us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MallBoulevard216KingofPrussiaPAMember
Buildings, Improvements & Equipment 2,871us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MallBoulevard216KingofPrussiaPAMember
Cost Capitalized Subsequent to Acquisition 83snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MallBoulevard216KingofPrussiaPAMember
Cost at the end of the period  
Land 880us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MallBoulevard216KingofPrussiaPAMember
Buildings, Improvements & Equipment 2,954us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MallBoulevard216KingofPrussiaPAMember
Total 3,834us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MallBoulevard216KingofPrussiaPAMember
Accumulated Depreciation 282us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MallBoulevard216KingofPrussiaPAMember
5300 Old William Penn Highway, Murrysville, PA  
Initial Cost to Company  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldWilliamPennHighway5300MurrysvillePAMember
Buildings, Improvements & Equipment 2,506us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldWilliamPennHighway5300MurrysvillePAMember
Cost at the end of the period  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldWilliamPennHighway5300MurrysvillePAMember
Buildings, Improvements & Equipment 2,506us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldWilliamPennHighway5300MurrysvillePAMember
Total 2,806us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldWilliamPennHighway5300MurrysvillePAMember
Accumulated Depreciation 932us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldWilliamPennHighway5300MurrysvillePAMember
800 Manor Drive, New Britain (Chalfont), PA  
Initial Cost to Company  
Land 979us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ManorDrive800NewBritainChalfontPAMember
Buildings, Improvements & Equipment 8,052us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ManorDrive800NewBritainChalfontPAMember
Cost Capitalized Subsequent to Acquisition 537snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ManorDrive800NewBritainChalfontPAMember
Cost at the end of the period  
Land 979us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ManorDrive800NewBritainChalfontPAMember
Buildings, Improvements & Equipment 8,589us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ManorDrive800NewBritainChalfontPAMember
Total 9,568us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ManorDrive800NewBritainChalfontPAMember
Accumulated Depreciation 2,601us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ManorDrive800NewBritainChalfontPAMember
7151 Saltsburg Road, Penn Hills, PA  
Initial Cost to Company  
Land 200us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SaltsburgRoad7151PennHillsPAMember
Buildings, Improvements & Equipment 904us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SaltsburgRoad7151PennHillsPAMember
Cost at the end of the period  
Land 200us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SaltsburgRoad7151PennHillsPAMember
Buildings, Improvements & Equipment 904us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SaltsburgRoad7151PennHillsPAMember
Total 1,104us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SaltsburgRoad7151PennHillsPAMember
Accumulated Depreciation 339us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SaltsburgRoad7151PennHillsPAMember
5750 Centre Ave, Pittsburgh, PA  
Initial Cost to Company  
Land 3,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentreAve5750PittsburghPAMember
Buildings, Improvements & Equipment 11,828us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentreAve5750PittsburghPAMember
Cost Capitalized Subsequent to Acquisition 1,055snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentreAve5750PittsburghPAMember
Cost at the end of the period  
Land 3,000us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentreAve5750PittsburghPAMember
Buildings, Improvements & Equipment 12,883us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentreAve5750PittsburghPAMember
Total 15,883us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentreAve5750PittsburghPAMember
Accumulated Depreciation 2,272us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CentreAve5750PittsburghPAMember
730 Holiday Drive, Pittsburgh, PA  
Initial Cost to Company  
Land 2,480us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HolidayDrive730PittsburghPAMember
Buildings, Improvements & Equipment 6,395us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HolidayDrive730PittsburghPAMember
Cost Capitalized Subsequent to Acquisition 1,151snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HolidayDrive730PittsburghPAMember
Cost at the end of the period  
Land 2,480us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HolidayDrive730PittsburghPAMember
Buildings, Improvements & Equipment 7,546us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HolidayDrive730PittsburghPAMember
Total 10,026us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HolidayDrive730PittsburghPAMember
Accumulated Depreciation 728us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HolidayDrive730PittsburghPAMember
3043 Walton Road, Plymouth Meeting, PA  
Initial Cost to Company  
Land 1,680us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaltonRoad3043PlymouthMeetingPAMember
Buildings, Improvements & Equipment 9,187us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaltonRoad3043PlymouthMeetingPAMember
Cost Capitalized Subsequent to Acquisition 139snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaltonRoad3043PlymouthMeetingPAMember
Cost at the end of the period  
Land 1,713us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaltonRoad3043PlymouthMeetingPAMember
Buildings, Improvements & Equipment 9,293us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaltonRoad3043PlymouthMeetingPAMember
Total 11,006us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaltonRoad3043PlymouthMeetingPAMember
Accumulated Depreciation 752us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WaltonRoad3043PlymouthMeetingPAMember
1400 Riggs Road, South Park, PA  
Initial Cost to Company  
Land 898us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiggsRoad1400SouthParkPAMember
Buildings, Improvements & Equipment 8,102us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiggsRoad1400SouthParkPAMember
Cost Capitalized Subsequent to Acquisition 248snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiggsRoad1400SouthParkPAMember
Cost at the end of the period  
Land 898us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiggsRoad1400SouthParkPAMember
Buildings, Improvements & Equipment 8,350us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiggsRoad1400SouthParkPAMember
Total 9,248us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiggsRoad1400SouthParkPAMember
Accumulated Depreciation 2,220us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiggsRoad1400SouthParkPAMember
700 Northampton Street, Tiffany Court (Kingston), PA  
Initial Cost to Company  
Buildings, Improvements & Equipment 5,682us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthamptonStreet700TiffanyCourtKingstonPAMember
Cost Capitalized Subsequent to Acquisition 1,420snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthamptonStreet700TiffanyCourtKingstonPAMember
Cost at the end of the period  
Buildings, Improvements & Equipment 7,102us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthamptonStreet700TiffanyCourtKingstonPAMember
Total 7,102us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthamptonStreet700TiffanyCourtKingstonPAMember
Accumulated Depreciation 2,041us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthamptonStreet700TiffanyCourtKingstonPAMember
5250 Meadowgreen Drive, Whitehall, PA  
Initial Cost to Company  
Land 1,599us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MeadowgreenDrive5250WhitehallPAMember
Buildings, Improvements & Equipment 14,401us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MeadowgreenDrive5250WhitehallPAMember
Cost Capitalized Subsequent to Acquisition 1,211snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MeadowgreenDrive5250WhitehallPAMember
Cost at the end of the period  
Land 1,599us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MeadowgreenDrive5250WhitehallPAMember
Buildings, Improvements & Equipment 15,612us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MeadowgreenDrive5250WhitehallPAMember
Total 17,211us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MeadowgreenDrive5250WhitehallPAMember
Accumulated Depreciation 4,105us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MeadowgreenDrive5250WhitehallPAMember
1304 McLees Road, Anderson, SC  
Initial Cost to Company  
Land 295us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McLeesRoad1304AndersonSCMember
Buildings, Improvements & Equipment 3,509us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McLeesRoad1304AndersonSCMember
Cost Capitalized Subsequent to Acquisition 213snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McLeesRoad1304AndersonSCMember
Cost at the end of the period  
Land 295us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McLeesRoad1304AndersonSCMember
Buildings, Improvements & Equipment 3,722us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McLeesRoad1304AndersonSCMember
Total 4,017us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McLeesRoad1304AndersonSCMember
Accumulated Depreciation 1,052us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_McLeesRoad1304AndersonSCMember
109 Old Salem Road, Beaufort, SC  
Initial Cost to Company  
Land 188us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldSalemRoad109BeaufortSCMember
Buildings, Improvements & Equipment 2,234us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldSalemRoad109BeaufortSCMember
Cost Capitalized Subsequent to Acquisition 601snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldSalemRoad109BeaufortSCMember
Cost at the end of the period  
Land 188us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldSalemRoad109BeaufortSCMember
Buildings, Improvements & Equipment 2,835us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldSalemRoad109BeaufortSCMember
Total 3,023us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldSalemRoad109BeaufortSCMember
Accumulated Depreciation 947us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldSalemRoad109BeaufortSCMember
1119 Pick Pocket Plantation Drive, Beaufort, SC  
Initial Cost to Company  
Land 1,200us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PickPocketPlantationDrive1119BeaufortSCMember
Buildings, Improvements & Equipment 10,810us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PickPocketPlantationDrive1119BeaufortSCMember
Cost Capitalized Subsequent to Acquisition 417snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PickPocketPlantationDrive1119BeaufortSCMember
Cost at the end of the period  
Land 1,200us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PickPocketPlantationDrive1119BeaufortSCMember
Buildings, Improvements & Equipment 11,227us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PickPocketPlantationDrive1119BeaufortSCMember
Total 12,427us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PickPocketPlantationDrive1119BeaufortSCMember
Accumulated Depreciation 1,146us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PickPocketPlantationDrive1119BeaufortSCMember
719 Kershaw Highway, Camden, SC  
Initial Cost to Company  
Land 322us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KershawHighway719CamdenSCMember
Buildings, Improvements & Equipment 3,697us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KershawHighway719CamdenSCMember
Cost Capitalized Subsequent to Acquisition 908snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KershawHighway719CamdenSCMember
Cost at the end of the period  
Land 322us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KershawHighway719CamdenSCMember
Buildings, Improvements & Equipment 4,605us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KershawHighway719CamdenSCMember
Total 4,927us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KershawHighway719CamdenSCMember
Accumulated Depreciation 1,321us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KershawHighway719CamdenSCMember
2333 Ashley River Road, Charleston (4), SC  
Initial Cost to Company  
Land 848us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AshleyRiverRoad2333Charleston4SCMember
Buildings, Improvements & Equipment 14,000us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AshleyRiverRoad2333Charleston4SCMember
Cost Capitalized Subsequent to Acquisition 351snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AshleyRiverRoad2333Charleston4SCMember
Cost at the end of the period  
Land 848us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AshleyRiverRoad2333Charleston4SCMember
Buildings, Improvements & Equipment 14,351us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AshleyRiverRoad2333Charleston4SCMember
Total 15,199us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AshleyRiverRoad2333Charleston4SCMember
Accumulated Depreciation 1,374us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AshleyRiverRoad2333Charleston4SCMember
320 Seven Farms Drive, Charleston (4), SC  
Real Estate And Accumulated Depreciation  
Encumbrances 4,594us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SevenFarmsDrive320Charleston4SCMember
Initial Cost to Company  
Land 1,092us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SevenFarmsDrive320Charleston4SCMember
Buildings, Improvements & Equipment 6,605us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SevenFarmsDrive320Charleston4SCMember
Cost Capitalized Subsequent to Acquisition 264snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SevenFarmsDrive320Charleston4SCMember
Cost at the end of the period  
Land 1,092us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SevenFarmsDrive320Charleston4SCMember
Buildings, Improvements & Equipment 6,869us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SevenFarmsDrive320Charleston4SCMember
Total 7,961us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SevenFarmsDrive320Charleston4SCMember
Accumulated Depreciation 502us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SevenFarmsDrive320Charleston4SCMember
201 Executive Center Drive, Columbia, SC  
Initial Cost to Company  
Land 390us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveCenterDrive201ColumbiaSCMember
Buildings, Improvements & Equipment 4,659us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveCenterDrive201ColumbiaSCMember
Cost Capitalized Subsequent to Acquisition 332snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveCenterDrive201ColumbiaSCMember
Cost at the end of the period  
Land 390us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveCenterDrive201ColumbiaSCMember
Buildings, Improvements & Equipment 4,991us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveCenterDrive201ColumbiaSCMember
Total 5,381us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveCenterDrive201ColumbiaSCMember
Accumulated Depreciation 474us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ExecutiveCenterDrive201ColumbiaSCMember
251 Springtree Drive, Columbia, SC  
Initial Cost to Company  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SpringtreeDrive251ColumbiaSCMember
Buildings, Improvements & Equipment 1,905us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SpringtreeDrive251ColumbiaSCMember
Cost at the end of the period  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SpringtreeDrive251ColumbiaSCMember
Buildings, Improvements & Equipment 1,905us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SpringtreeDrive251ColumbiaSCMember
Total 2,205us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SpringtreeDrive251ColumbiaSCMember
Accumulated Depreciation 643us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SpringtreeDrive251ColumbiaSCMember
3 Summit Terrace, Columbia, SC  
Initial Cost to Company  
Land 610us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SummitTerrace3ColumbiaSCMember
Buildings, Improvements & Equipment 7,900us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SummitTerrace3ColumbiaSCMember
Cost Capitalized Subsequent to Acquisition 751snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SummitTerrace3ColumbiaSCMember
Cost at the end of the period  
Land 610us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SummitTerrace3ColumbiaSCMember
Buildings, Improvements & Equipment 8,651us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SummitTerrace3ColumbiaSCMember
Total 9,261us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SummitTerrace3ColumbiaSCMember
Accumulated Depreciation 1,159us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SummitTerrace3ColumbiaSCMember
7909 Parklane Road, Columbia, SC  
Initial Cost to Company  
Land 1,580us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParklaneRoad7909ColumbiaSCMember
Buildings, Improvements & Equipment 4,520us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParklaneRoad7909ColumbiaSCMember
Cost Capitalized Subsequent to Acquisition 296snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParklaneRoad7909ColumbiaSCMember
Cost at the end of the period  
Land 1,580us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParklaneRoad7909ColumbiaSCMember
Buildings, Improvements & Equipment 4,816us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParklaneRoad7909ColumbiaSCMember
Total 6,396us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParklaneRoad7909ColumbiaSCMember
Accumulated Depreciation 380us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParklaneRoad7909ColumbiaSCMember
355 Berkmans Lane, Greenville, SC  
Initial Cost to Company  
Land 700us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BerkmansLane355GreenvilleSCMember
Buildings, Improvements & Equipment 7,240us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BerkmansLane355GreenvilleSCMember
Cost Capitalized Subsequent to Acquisition 88snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BerkmansLane355GreenvilleSCMember
Cost at the end of the period  
Land 700us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BerkmansLane355GreenvilleSCMember
Buildings, Improvements & Equipment 7,328us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BerkmansLane355GreenvilleSCMember
Total 8,028us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BerkmansLane355GreenvilleSCMember
Accumulated Depreciation 1,068us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BerkmansLane355GreenvilleSCMember
116 Enterprise Court, Greenwood, SC  
Initial Cost to Company  
Land 310us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EnterpriseCourt116GreenwoodSCMember
Buildings, Improvements & Equipment 2,790us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EnterpriseCourt116GreenwoodSCMember
Cost Capitalized Subsequent to Acquisition 193snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EnterpriseCourt116GreenwoodSCMember
Cost at the end of the period  
Land 310us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EnterpriseCourt116GreenwoodSCMember
Buildings, Improvements & Equipment 2,983us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EnterpriseCourt116GreenwoodSCMember
Total 3,293us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EnterpriseCourt116GreenwoodSCMember
Accumulated Depreciation 821us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EnterpriseCourt116GreenwoodSCMember
1901 West Carolina, Hartsville, SC  
Initial Cost to Company  
Land 401us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestCarolina1901HartsvilleSCMember
Buildings, Improvements & Equipment 4,775us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestCarolina1901HartsvilleSCMember
Cost Capitalized Subsequent to Acquisition 571snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestCarolina1901HartsvilleSCMember
Cost at the end of the period  
Land 401us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestCarolina1901HartsvilleSCMember
Buildings, Improvements & Equipment 5,346us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestCarolina1901HartsvilleSCMember
Total 5,747us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestCarolina1901HartsvilleSCMember
Accumulated Depreciation 1,492us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestCarolina1901HartsvilleSCMember
218 Old Chapin Road, Lexington, SC  
Initial Cost to Company  
Land 363us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldChapinRoad218LexingtonSCMember
Buildings, Improvements & Equipment 4,322us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldChapinRoad218LexingtonSCMember
Cost Capitalized Subsequent to Acquisition 402snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldChapinRoad218LexingtonSCMember
Cost at the end of the period  
Land 363us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldChapinRoad218LexingtonSCMember
Buildings, Improvements & Equipment 4,724us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldChapinRoad218LexingtonSCMember
Total 5,087us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldChapinRoad218LexingtonSCMember
Accumulated Depreciation 1,365us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OldChapinRoad218LexingtonSCMember
491 Highway 17, Little River (4), SC  
Real Estate And Accumulated Depreciation  
Encumbrances 4,887us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Highway17491LittleRiver4SCMember
Initial Cost to Company  
Land 750us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Highway17491LittleRiver4SCMember
Buildings, Improvements & Equipment 9,018us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Highway17491LittleRiver4SCMember
Cost Capitalized Subsequent to Acquisition 248snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Highway17491LittleRiver4SCMember
Cost at the end of the period  
Land 750us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Highway17491LittleRiver4SCMember
Buildings, Improvements & Equipment 9,266us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Highway17491LittleRiver4SCMember
Total 10,016us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Highway17491LittleRiver4SCMember
Accumulated Depreciation 879us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Highway17491LittleRiver4SCMember
1010 Lake Hunter Circle / 987 Bowman Road, Mt. Pleasant, SC  
Initial Cost to Company  
Land 3,898us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeHunterCircle1010AndBowmanRoad987MtPleasantSCMember
Buildings, Improvements & Equipment 31,613us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeHunterCircle1010AndBowmanRoad987MtPleasantSCMember
Cost Capitalized Subsequent to Acquisition 1,748snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeHunterCircle1010AndBowmanRoad987MtPleasantSCMember
Cost at the end of the period  
Land 3,898us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeHunterCircle1010AndBowmanRoad987MtPleasantSCMember
Buildings, Improvements & Equipment 33,361us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeHunterCircle1010AndBowmanRoad987MtPleasantSCMember
Total 37,259us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeHunterCircle1010AndBowmanRoad987MtPleasantSCMember
Accumulated Depreciation 2,317us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LakeHunterCircle1010AndBowmanRoad987MtPleasantSCMember
9547 Highway 17 North, Myrtle Beach, SC  
Initial Cost to Company  
Land 543us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Highway17North9547MyrtleBeachSCMember
Buildings, Improvements & Equipment 3,202us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Highway17North9547MyrtleBeachSCMember
Cost Capitalized Subsequent to Acquisition 7,756snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Highway17North9547MyrtleBeachSCMember
Cost at the end of the period  
Land 543us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Highway17North9547MyrtleBeachSCMember
Buildings, Improvements & Equipment 10,958us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Highway17North9547MyrtleBeachSCMember
Total 11,501us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Highway17North9547MyrtleBeachSCMember
Accumulated Depreciation 2,313us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Highway17North9547MyrtleBeachSCMember
2306 Riverbank Drive, Orangeburg, SC  
Initial Cost to Company  
Land 303us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiverbankDrive2306OrangeburgSCMember
Buildings, Improvements & Equipment 3,607us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiverbankDrive2306OrangeburgSCMember
Cost Capitalized Subsequent to Acquisition 690snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiverbankDrive2306OrangeburgSCMember
Cost at the end of the period  
Land 303us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiverbankDrive2306OrangeburgSCMember
Buildings, Improvements & Equipment 4,297us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiverbankDrive2306OrangeburgSCMember
Total 4,600us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiverbankDrive2306OrangeburgSCMember
Accumulated Depreciation 1,231us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiverbankDrive2306OrangeburgSCMember
1920 Ebenezer Road, Rock Hill, SC  
Initial Cost to Company  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EbenezerRoad1920RockHillSCMember
Buildings, Improvements & Equipment 1,705us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EbenezerRoad1920RockHillSCMember
Cost at the end of the period  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EbenezerRoad1920RockHillSCMember
Buildings, Improvements & Equipment 1,705us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EbenezerRoad1920RockHillSCMember
Total 2,005us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EbenezerRoad1920RockHillSCMember
Accumulated Depreciation 618us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EbenezerRoad1920RockHillSCMember
15855 Wells Highway, Seneca, SC  
Initial Cost to Company  
Land 396us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WellsHighway15855SenecaSCMember
Buildings, Improvements & Equipment 4,714us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WellsHighway15855SenecaSCMember
Cost Capitalized Subsequent to Acquisition 470snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WellsHighway15855SenecaSCMember
Cost at the end of the period  
Land 396us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WellsHighway15855SenecaSCMember
Buildings, Improvements & Equipment 5,184us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WellsHighway15855SenecaSCMember
Total 5,580us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WellsHighway15855SenecaSCMember
Accumulated Depreciation 1,449us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WellsHighway15855SenecaSCMember
One Southern Court, West Columbia, SC  
Initial Cost to Company  
Land 520us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OneSouthernCourtWestColumbiaSCMember
Buildings, Improvements & Equipment 3,831us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OneSouthernCourtWestColumbiaSCMember
Cost at the end of the period  
Land 520us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OneSouthernCourtWestColumbiaSCMember
Buildings, Improvements & Equipment 3,831us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OneSouthernCourtWestColumbiaSCMember
Total 4,351us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OneSouthernCourtWestColumbiaSCMember
Accumulated Depreciation 383us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_OneSouthernCourtWestColumbiaSCMember
1251 Arizona S.W., Huron, SD  
Initial Cost to Company  
Land 45us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ArizonaSW1251HuronSDMember
Buildings, Improvements & Equipment 968us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ArizonaSW1251HuronSDMember
Cost Capitalized Subsequent to Acquisition 1snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ArizonaSW1251HuronSDMember
Cost at the end of the period  
Land 45us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ArizonaSW1251HuronSDMember
Buildings, Improvements & Equipment 969us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ArizonaSW1251HuronSDMember
Total 1,014us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ArizonaSW1251HuronSDMember
Accumulated Depreciation 567us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ArizonaSW1251HuronSDMember
1345 Michigan Ave SW, Huron, SD  
Initial Cost to Company  
Land 144us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MichiganAveSW1345HuronSDMember
Buildings, Improvements & Equipment 3,108us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MichiganAveSW1345HuronSDMember
Cost Capitalized Subsequent to Acquisition 4snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MichiganAveSW1345HuronSDMember
Cost at the end of the period  
Land 144us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MichiganAveSW1345HuronSDMember
Buildings, Improvements & Equipment 3,112us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MichiganAveSW1345HuronSDMember
Total 3,256us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MichiganAveSW1345HuronSDMember
Accumulated Depreciation 1,821us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MichiganAveSW1345HuronSDMember
3600 S. Norton, Sioux Falls, SD  
Initial Cost to Company  
Land 253us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SNorton3600SiouxFallsSDMember
Buildings, Improvements & Equipment 3,062us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SNorton3600SiouxFallsSDMember
Cost Capitalized Subsequent to Acquisition 4snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SNorton3600SiouxFallsSDMember
Cost at the end of the period  
Land 253us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SNorton3600SiouxFallsSDMember
Buildings, Improvements & Equipment 3,066us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SNorton3600SiouxFallsSDMember
Total 3,319us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SNorton3600SiouxFallsSDMember
Accumulated Depreciation 1,797us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SNorton3600SiouxFallsSDMember
6716 Nolensville Road, Brentwood, TN  
Initial Cost to Company  
Land 1,528us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NolensvilleRoad6716BrentwoodTNMember
Buildings, Improvements & Equipment 6,037us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NolensvilleRoad6716BrentwoodTNMember
Cost Capitalized Subsequent to Acquisition 16snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NolensvilleRoad6716BrentwoodTNMember
Cost at the end of the period  
Land 1,528us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NolensvilleRoad6716BrentwoodTNMember
Buildings, Improvements & Equipment 6,053us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NolensvilleRoad6716BrentwoodTNMember
Total 7,581us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NolensvilleRoad6716BrentwoodTNMember
Accumulated Depreciation 314us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NolensvilleRoad6716BrentwoodTNMember
207 Uffelman Drive, Clarksville, TN  
Initial Cost to Company  
Land 320us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UffelmanDrive207ClarksvilleTNMember
Buildings, Improvements & Equipment 2,994us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UffelmanDrive207ClarksvilleTNMember
Cost Capitalized Subsequent to Acquisition 611snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UffelmanDrive207ClarksvilleTNMember
Cost at the end of the period  
Land 320us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UffelmanDrive207ClarksvilleTNMember
Buildings, Improvements & Equipment 3,605us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UffelmanDrive207ClarksvilleTNMember
Total 3,925us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UffelmanDrive207ClarksvilleTNMember
Accumulated Depreciation 765us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_UffelmanDrive207ClarksvilleTNMember
51 Patel Way, Clarksville, TN  
Initial Cost to Company  
Land 800us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PatelWay51ClarksvilleTNMember
Buildings, Improvements & Equipment 10,322us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PatelWay51ClarksvilleTNMember
Cost Capitalized Subsequent to Acquisition 591snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PatelWay51ClarksvilleTNMember
Cost at the end of the period  
Land 800us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PatelWay51ClarksvilleTNMember
Buildings, Improvements & Equipment 10,913us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PatelWay51ClarksvilleTNMember
Total 11,713us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PatelWay51ClarksvilleTNMember
Accumulated Depreciation 627us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PatelWay51ClarksvilleTNMember
2900 Westside Drive, Cleveland, TN  
Initial Cost to Company  
Land 305us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestsideDrive2900ClevelandTNMember
Buildings, Improvements & Equipment 3,627us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestsideDrive2900ClevelandTNMember
Cost Capitalized Subsequent to Acquisition 682snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestsideDrive2900ClevelandTNMember
Cost at the end of the period  
Land 305us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestsideDrive2900ClevelandTNMember
Buildings, Improvements & Equipment 4,309us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestsideDrive2900ClevelandTNMember
Total 4,614us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestsideDrive2900ClevelandTNMember
Accumulated Depreciation 1,187us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestsideDrive2900ClevelandTNMember
1010 East Spring Street, Cookeville, TN  
Initial Cost to Company  
Land 322us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastSpringStreet1010CookevilleTNMember
Buildings, Improvements & Equipment 3,828us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastSpringStreet1010CookevilleTNMember
Cost Capitalized Subsequent to Acquisition 583snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastSpringStreet1010CookevilleTNMember
Cost at the end of the period  
Land 322us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastSpringStreet1010CookevilleTNMember
Buildings, Improvements & Equipment 4,411us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastSpringStreet1010CookevilleTNMember
Total 4,733us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastSpringStreet1010CookevilleTNMember
Accumulated Depreciation 1,198us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastSpringStreet1010CookevilleTNMember
105 Sunrise Circle, Franklin, TN  
Initial Cost to Company  
Land 322us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SunriseCircle105FranklinTNMember
Buildings, Improvements & Equipment 3,833us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SunriseCircle105FranklinTNMember
Cost Capitalized Subsequent to Acquisition 585snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SunriseCircle105FranklinTNMember
Cost at the end of the period  
Land 322us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SunriseCircle105FranklinTNMember
Buildings, Improvements & Equipment 4,418us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SunriseCircle105FranklinTNMember
Total 4,740us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SunriseCircle105FranklinTNMember
Accumulated Depreciation 1,199us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SunriseCircle105FranklinTNMember
1085 Hartsville Pike, Gallatin, TN  
Initial Cost to Company  
Land 280us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HartsvillePike1085GallatinTNMember
Buildings, Improvements & Equipment 3,327us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HartsvillePike1085GallatinTNMember
Cost Capitalized Subsequent to Acquisition 245snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HartsvillePike1085GallatinTNMember
Cost at the end of the period  
Land 280us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HartsvillePike1085GallatinTNMember
Buildings, Improvements & Equipment 3,572us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HartsvillePike1085GallatinTNMember
Total 3,852us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HartsvillePike1085GallatinTNMember
Accumulated Depreciation 1,003us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HartsvillePike1085GallatinTNMember
2025 Caldwell Drive, Goodlettsville, TN  
Initial Cost to Company  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CaldwellDrive2025GoodlettsvilleTNMember
Buildings, Improvements & Equipment 3,507us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CaldwellDrive2025GoodlettsvilleTNMember
Cost at the end of the period  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CaldwellDrive2025GoodlettsvilleTNMember
Buildings, Improvements & Equipment 3,507us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CaldwellDrive2025GoodlettsvilleTNMember
Total 3,907us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CaldwellDrive2025GoodlettsvilleTNMember
Accumulated Depreciation 1,181us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CaldwellDrive2025GoodlettsvilleTNMember
1200 North Parkway, Jackson, TN  
Initial Cost to Company  
Land 295us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthParkway1200JacksonTNMember
Buildings, Improvements & Equipment 3,506us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthParkway1200JacksonTNMember
Cost Capitalized Subsequent to Acquisition 312snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthParkway1200JacksonTNMember
Cost at the end of the period  
Land 295us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthParkway1200JacksonTNMember
Buildings, Improvements & Equipment 3,818us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthParkway1200JacksonTNMember
Total 4,113us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthParkway1200JacksonTNMember
Accumulated Depreciation 1,099us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthParkway1200JacksonTNMember
550 Deer View Way, Jefferson City, TN  
Initial Cost to Company  
Land 940us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerViewWay550JeffersonCityTNMember
Buildings, Improvements & Equipment 8,057us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerViewWay550JeffersonCityTNMember
Cost Capitalized Subsequent to Acquisition 354snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerViewWay550JeffersonCityTNMember
Cost at the end of the period  
Land 940us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerViewWay550JeffersonCityTNMember
Buildings, Improvements & Equipment 8,411us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerViewWay550JeffersonCityTNMember
Total 9,351us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerViewWay550JeffersonCityTNMember
Accumulated Depreciation 276us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DeerViewWay550JeffersonCityTNMember
3020 Heatherton Way, Knoxville, TN  
Initial Cost to Company  
Land 304us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HeathertonWay3020KnoxvilleTNMember
Buildings, Improvements & Equipment 3,618us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HeathertonWay3020KnoxvilleTNMember
Cost Capitalized Subsequent to Acquisition 1,803snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HeathertonWay3020KnoxvilleTNMember
Cost at the end of the period  
Land 304us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HeathertonWay3020KnoxvilleTNMember
Buildings, Improvements & Equipment 5,421us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HeathertonWay3020KnoxvilleTNMember
Total 5,725us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HeathertonWay3020KnoxvilleTNMember
Accumulated Depreciation 1,409us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HeathertonWay3020KnoxvilleTNMember
511 Pearson Springs Road, Maryville, TN  
Initial Cost to Company  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PearsonSpringsRoad511MaryvilleTNMember
Buildings, Improvements & Equipment 3,207us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PearsonSpringsRoad511MaryvilleTNMember
Cost Capitalized Subsequent to Acquisition 100snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PearsonSpringsRoad511MaryvilleTNMember
Cost at the end of the period  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PearsonSpringsRoad511MaryvilleTNMember
Buildings, Improvements & Equipment 3,307us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PearsonSpringsRoad511MaryvilleTNMember
Total 3,607us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PearsonSpringsRoad511MaryvilleTNMember
Accumulated Depreciation 1,115us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PearsonSpringsRoad511MaryvilleTNMember
1710 Magnolia Blvd, Nashville, TN  
Initial Cost to Company  
Land 750us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MagnoliaBlvd1710NashvilleTNMember
Buildings, Improvements & Equipment 6,750us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MagnoliaBlvd1710NashvilleTNMember
Cost Capitalized Subsequent to Acquisition 4,177snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MagnoliaBlvd1710NashvilleTNMember
Cost at the end of the period  
Land 750us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MagnoliaBlvd1710NashvilleTNMember
Buildings, Improvements & Equipment 10,927us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MagnoliaBlvd1710NashvilleTNMember
Total 11,677us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MagnoliaBlvd1710NashvilleTNMember
Accumulated Depreciation 2,567us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MagnoliaBlvd1710NashvilleTNMember
971 State Hwy 121, Allen, TX  
Initial Cost to Company  
Land 2,590us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateHwy121971AllenTXMember
Buildings, Improvements & Equipment 17,912us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateHwy121971AllenTXMember
Cost at the end of the period  
Land 2,590us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateHwy121971AllenTXMember
Buildings, Improvements & Equipment 17,912us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateHwy121971AllenTXMember
Total 20,502us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateHwy121971AllenTXMember
Accumulated Depreciation 2,855us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_StateHwy121971AllenTXMember
6818 Austin Center Blvd, Austin, TX  
Initial Cost to Company  
Land 1,540us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AustinCenterBlvd6818AustinTXMember
Buildings, Improvements & Equipment 27,467us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AustinCenterBlvd6818AustinTXMember
Cost Capitalized Subsequent to Acquisition 784snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AustinCenterBlvd6818AustinTXMember
Cost at the end of the period  
Land 1,540us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AustinCenterBlvd6818AustinTXMember
Buildings, Improvements & Equipment 28,251us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AustinCenterBlvd6818AustinTXMember
Total 29,791us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AustinCenterBlvd6818AustinTXMember
Accumulated Depreciation 4,452us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AustinCenterBlvd6818AustinTXMember
6937 IH 35 North-Am Founders, Austin, TX  
Initial Cost to Company  
Land 760us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IH35NorthAmFounders6937AustinTXMember
Buildings, Improvements & Equipment 5,186us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IH35NorthAmFounders6937AustinTXMember
Cost Capitalized Subsequent to Acquisition 441snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IH35NorthAmFounders6937AustinTXMember
Cost at the end of the period  
Land 760us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IH35NorthAmFounders6937AustinTXMember
Buildings, Improvements & Equipment 5,627us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IH35NorthAmFounders6937AustinTXMember
Total 6,387us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IH35NorthAmFounders6937AustinTXMember
Accumulated Depreciation 657us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IH35NorthAmFounders6937AustinTXMember
7600 Capital Texas Highway, Austin, TX  
Initial Cost to Company  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CapitalTexasHighway7600AustinTXMember
Buildings, Improvements & Equipment 4,557us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CapitalTexasHighway7600AustinTXMember
Cost at the end of the period  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CapitalTexasHighway7600AustinTXMember
Buildings, Improvements & Equipment 4,557us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CapitalTexasHighway7600AustinTXMember
Total 4,857us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CapitalTexasHighway7600AustinTXMember
Accumulated Depreciation 456us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CapitalTexasHighway7600AustinTXMember
Bailey Square (1111 W 34th St), Austin, TX  
Initial Cost to Company  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Square1111W34thStBaileyAustinTXMember
Buildings, Improvements & Equipment 21,021us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Square1111W34thStBaileyAustinTXMember
Cost Capitalized Subsequent to Acquisition 799snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Square1111W34thStBaileyAustinTXMember
Cost at the end of the period  
Land 400us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Square1111W34thStBaileyAustinTXMember
Buildings, Improvements & Equipment 21,820us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Square1111W34thStBaileyAustinTXMember
Total 22,220us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Square1111W34thStBaileyAustinTXMember
Accumulated Depreciation 3,511us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Square1111W34thStBaileyAustinTXMember
4620 Bellaire Boulevard, Bellaire, TX  
Initial Cost to Company  
Land 1,238us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BellaireBoulevard4620BellaireTXMember
Buildings, Improvements & Equipment 11,010us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BellaireBoulevard4620BellaireTXMember
Cost Capitalized Subsequent to Acquisition 1,427snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BellaireBoulevard4620BellaireTXMember
Cost at the end of the period  
Land 1,238us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BellaireBoulevard4620BellaireTXMember
Buildings, Improvements & Equipment 12,437us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BellaireBoulevard4620BellaireTXMember
Total 13,675us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BellaireBoulevard4620BellaireTXMember
Accumulated Depreciation 5,916us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BellaireBoulevard4620BellaireTXMember
120 Crosspoint Drive, Boerne, TX  
Initial Cost to Company  
Land 220us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrosspointDrive120BoerneTXMember
Buildings, Improvements & Equipment 4,926us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrosspointDrive120BoerneTXMember
Cost Capitalized Subsequent to Acquisition 134snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrosspointDrive120BoerneTXMember
Cost at the end of the period  
Land 220us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrosspointDrive120BoerneTXMember
Buildings, Improvements & Equipment 5,060us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrosspointDrive120BoerneTXMember
Total 5,280us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrosspointDrive120BoerneTXMember
Accumulated Depreciation 871us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrosspointDrive120BoerneTXMember
4015 Interstate 45, Conroe , TX  
Initial Cost to Company  
Land 620us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Interstate454015ConroeTXMember
Buildings, Improvements & Equipment 14,074us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Interstate454015ConroeTXMember
Cost Capitalized Subsequent to Acquisition 78snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Interstate454015ConroeTXMember
Cost at the end of the period  
Land 620us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Interstate454015ConroeTXMember
Buildings, Improvements & Equipment 14,152us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Interstate454015ConroeTXMember
Total 14,772us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Interstate454015ConroeTXMember
Accumulated Depreciation 1,475us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Interstate454015ConroeTXMember
5455 La Sierra Drive, Dallas, TX  
Initial Cost to Company  
Land 2,300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LaSierraDrive5455DallasTXMember
Buildings, Improvements & Equipment 25,200us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LaSierraDrive5455DallasTXMember
Cost Capitalized Subsequent to Acquisition 684snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LaSierraDrive5455DallasTXMember
Cost at the end of the period  
Land 2,300us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LaSierraDrive5455DallasTXMember
Buildings, Improvements & Equipment 25,884us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LaSierraDrive5455DallasTXMember
Total 28,184us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LaSierraDrive5455DallasTXMember
Accumulated Depreciation 2,267us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LaSierraDrive5455DallasTXMember
7831 Park Lane, Dallas, TX  
Initial Cost to Company  
Land 4,709us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkLane7831DallasTXMember
Buildings, Improvements & Equipment 27,768us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkLane7831DallasTXMember
Cost Capitalized Subsequent to Acquisition 6,631snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkLane7831DallasTXMember
Cost at the end of the period  
Land 4,709us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkLane7831DallasTXMember
Buildings, Improvements & Equipment 34,399us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkLane7831DallasTXMember
Total 39,108us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkLane7831DallasTXMember
Accumulated Depreciation 11,813us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ParkLane7831DallasTXMember
1575 Belvidere, El Paso, TX  
Initial Cost to Company  
Land 2,301us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Belvidere1575ElPasoTXMember
Buildings, Improvements & Equipment 13,567us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Belvidere1575ElPasoTXMember
Cost Capitalized Subsequent to Acquisition 2,492snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Belvidere1575ElPasoTXMember
Cost at the end of the period  
Land 2,301us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Belvidere1575ElPasoTXMember
Buildings, Improvements & Equipment 16,059us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Belvidere1575ElPasoTXMember
Total 18,360us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Belvidere1575ElPasoTXMember
Accumulated Depreciation 5,595us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Belvidere1575ElPasoTXMember
96 E. Frederick Rd., Fredericksburg, TX  
Initial Cost to Company  
Land 280us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EFrederickRd96FredericksburgTXMember
Buildings, Improvements & Equipment 4,866us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EFrederickRd96FredericksburgTXMember
Cost Capitalized Subsequent to Acquisition 811snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EFrederickRd96FredericksburgTXMember
Cost at the end of the period  
Land 280us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EFrederickRd96FredericksburgTXMember
Buildings, Improvements & Equipment 5,677us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EFrederickRd96FredericksburgTXMember
Total 5,957us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EFrederickRd96FredericksburgTXMember
Accumulated Depreciation 876us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EFrederickRd96FredericksburgTXMember
6435 S.F.M. 549, Heath, TX  
Initial Cost to Company  
Land 1,135us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SFM5496435HeathTXMember
Buildings, Improvements & Equipment 7,892us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SFM5496435HeathTXMember
Cost Capitalized Subsequent to Acquisition 1snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SFM5496435HeathTXMember
Cost at the end of the period  
Land 1,135us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SFM5496435HeathTXMember
Buildings, Improvements & Equipment 7,893us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SFM5496435HeathTXMember
Total 9,028us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SFM5496435HeathTXMember
Accumulated Depreciation 395us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SFM5496435HeathTXMember
13215 Dotson Road, Houston, TX  
Initial Cost to Company  
Land 990us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DotsonRoad13215HoustonTXMember
Buildings, Improvements & Equipment 13,887us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DotsonRoad13215HoustonTXMember
Cost at the end of the period  
Land 990us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DotsonRoad13215HoustonTXMember
Buildings, Improvements & Equipment 13,887us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DotsonRoad13215HoustonTXMember
Total 14,877us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DotsonRoad13215HoustonTXMember
Accumulated Depreciation 839us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DotsonRoad13215HoustonTXMember
777 North Post Oak Road, Houston, TX  
Initial Cost to Company  
Land 5,537us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthPostOakRoad777HoustonTXMember
Buildings, Improvements & Equipment 32,647us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthPostOakRoad777HoustonTXMember
Cost Capitalized Subsequent to Acquisition 11,117snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthPostOakRoad777HoustonTXMember
Cost at the end of the period  
Land 5,537us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthPostOakRoad777HoustonTXMember
Buildings, Improvements & Equipment 43,764us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthPostOakRoad777HoustonTXMember
Total 49,301us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthPostOakRoad777HoustonTXMember
Accumulated Depreciation 14,663us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthPostOakRoad777HoustonTXMember
4770 Regent Blvd, Irving, TX  
Initial Cost to Company  
Land 2,830us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RegentBlvd4770IrvingTXMember
Buildings, Improvements & Equipment 15,082us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RegentBlvd4770IrvingTXMember
Cost Capitalized Subsequent to Acquisition 10snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RegentBlvd4770IrvingTXMember
Cost at the end of the period  
Land 2,830us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RegentBlvd4770IrvingTXMember
Buildings, Improvements & Equipment 15,092us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RegentBlvd4770IrvingTXMember
Total 17,922us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RegentBlvd4770IrvingTXMember
Accumulated Depreciation 2,468us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RegentBlvd4770IrvingTXMember
9812 Slide Road, Lubbock, TX  
Initial Cost to Company  
Land 1,110us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SlideRoad9812LubbockTXMember
Buildings, Improvements & Equipment 9,804us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SlideRoad9812LubbockTXMember
Cost Capitalized Subsequent to Acquisition (6)snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SlideRoad9812LubbockTXMember
Cost at the end of the period  
Land 1,110us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SlideRoad9812LubbockTXMember
Buildings, Improvements & Equipment 9,798us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SlideRoad9812LubbockTXMember
Total 10,908us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SlideRoad9812LubbockTXMember
Accumulated Depreciation 1,123us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SlideRoad9812LubbockTXMember
605 Gateway Central / 601 Steve Hawkins Prkway, Marble Falls , TX  
Initial Cost to Company  
Land 1,440us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GatewayCentral605AndSteveHawkinsPrkway601MarbleFallsTXMember
Buildings, Improvements & Equipment 7,125us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GatewayCentral605AndSteveHawkinsPrkway601MarbleFallsTXMember
Cost Capitalized Subsequent to Acquisition 197snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GatewayCentral605AndSteveHawkinsPrkway601MarbleFallsTXMember
Cost at the end of the period  
Land 1,440us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GatewayCentral605AndSteveHawkinsPrkway601MarbleFallsTXMember
Buildings, Improvements & Equipment 7,322us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GatewayCentral605AndSteveHawkinsPrkway601MarbleFallsTXMember
Total 8,762us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GatewayCentral605AndSteveHawkinsPrkway601MarbleFallsTXMember
Accumulated Depreciation 428us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GatewayCentral605AndSteveHawkinsPrkway601MarbleFallsTXMember
7150 N. President George Bush Turnpike, North Garland, TX  
Initial Cost to Company  
Land 1,981us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPresidentGeorgeBushTurnpike7150NorthGarlandTXMember
Buildings, Improvements & Equipment 8,548us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPresidentGeorgeBushTurnpike7150NorthGarlandTXMember
Cost at the end of the period  
Land 1,981us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPresidentGeorgeBushTurnpike7150NorthGarlandTXMember
Buildings, Improvements & Equipment 8,548us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPresidentGeorgeBushTurnpike7150NorthGarlandTXMember
Total 10,529us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPresidentGeorgeBushTurnpike7150NorthGarlandTXMember
Accumulated Depreciation 427us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPresidentGeorgeBushTurnpike7150NorthGarlandTXMember
21 Spurs Lane, Antonio, TX  
Real Estate And Accumulated Depreciation  
Encumbrances 15,318us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SpursLane21SanAntonioTXMember
Initial Cost to Company  
Land 3,141us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SpursLane21SanAntonioTXMember
Buildings, Improvements & Equipment 23,142us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SpursLane21SanAntonioTXMember
Cost at the end of the period  
Land 3,141us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SpursLane21SanAntonioTXMember
Buildings, Improvements & Equipment 23,142us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SpursLane21SanAntonioTXMember
Total 26,283us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SpursLane21SanAntonioTXMember
Accumulated Depreciation 434us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SpursLane21SanAntonioTXMember
311 Nottingham West, San Antonio (4), TX  
Real Estate And Accumulated Depreciation  
Encumbrances 27,552us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NottinghamWest311SanAntonioTXMember
Initial Cost to Company  
Land 4,283us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NottinghamWest311SanAntonioTXMember
Buildings, Improvements & Equipment 25,256us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NottinghamWest311SanAntonioTXMember
Cost Capitalized Subsequent to Acquisition 5,729snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NottinghamWest311SanAntonioTXMember
Cost at the end of the period  
Land 4,283us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NottinghamWest311SanAntonioTXMember
Buildings, Improvements & Equipment 30,985us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NottinghamWest311SanAntonioTXMember
Total 35,268us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NottinghamWest311SanAntonioTXMember
Accumulated Depreciation 11,079us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NottinghamWest311SanAntonioTXMember
511 Knights Cross Drive, San Antonio, TX  
Initial Cost to Company  
Land 1,200us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsCrossDrive511SanAntonioTXMember
Buildings, Improvements & Equipment 6,500us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsCrossDrive511SanAntonioTXMember
Cost Capitalized Subsequent to Acquisition 24snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsCrossDrive511SanAntonioTXMember
Cost at the end of the period  
Land 1,200us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsCrossDrive511SanAntonioTXMember
Buildings, Improvements & Equipment 6,524us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsCrossDrive511SanAntonioTXMember
Total 7,724us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsCrossDrive511SanAntonioTXMember
Accumulated Depreciation 950us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsCrossDrive511SanAntonioTXMember
575 Knights Cross Drive, San Antonio, TX  
Initial Cost to Company  
Land 1,100us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsCrossDrive575SanAntonioTXMember
Buildings, Improvements & Equipment 13,900us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsCrossDrive575SanAntonioTXMember
Cost Capitalized Subsequent to Acquisition 375snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsCrossDrive575SanAntonioTXMember
Cost at the end of the period  
Land 1,100us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsCrossDrive575SanAntonioTXMember
Buildings, Improvements & Equipment 14,275us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsCrossDrive575SanAntonioTXMember
Total 15,375us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsCrossDrive575SanAntonioTXMember
Accumulated Depreciation 2,080us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KnightsCrossDrive575SanAntonioTXMember
5055 West Panther Creek Drive, Woodlands (4), TX  
Real Estate And Accumulated Depreciation  
Encumbrances 37,239us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestPantherCreekDrive5055WoodlandsTXMember
Initial Cost to Company  
Land 3,694us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestPantherCreekDrive5055WoodlandsTXMember
Buildings, Improvements & Equipment 21,782us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestPantherCreekDrive5055WoodlandsTXMember
Cost Capitalized Subsequent to Acquisition 3,945snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestPantherCreekDrive5055WoodlandsTXMember
Cost at the end of the period  
Land 3,694us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestPantherCreekDrive5055WoodlandsTXMember
Buildings, Improvements & Equipment 25,727us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestPantherCreekDrive5055WoodlandsTXMember
Total 29,421us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestPantherCreekDrive5055WoodlandsTXMember
Accumulated Depreciation 9,943us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestPantherCreekDrive5055WoodlandsTXMember
900 North Taylor Street, Arlington, VA  
Initial Cost to Company  
Land 1,885us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthTaylorStreet900ArlingtonVAMember
Buildings, Improvements & Equipment 16,734us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthTaylorStreet900ArlingtonVAMember
Cost Capitalized Subsequent to Acquisition 270snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthTaylorStreet900ArlingtonVAMember
Cost at the end of the period  
Land 1,885us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthTaylorStreet900ArlingtonVAMember
Buildings, Improvements & Equipment 17,004us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthTaylorStreet900ArlingtonVAMember
Total 18,889us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthTaylorStreet900ArlingtonVAMember
Accumulated Depreciation 8,697us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthTaylorStreet900ArlingtonVAMember
2610 Barracks Road, Charlottesville, VA  
Initial Cost to Company  
Land 2,976us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BarracksRoad2610CharlottesvilleVAMember
Buildings, Improvements & Equipment 26,422us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BarracksRoad2610CharlottesvilleVAMember
Cost Capitalized Subsequent to Acquisition 431snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BarracksRoad2610CharlottesvilleVAMember
Cost at the end of the period  
Land 2,976us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BarracksRoad2610CharlottesvilleVAMember
Buildings, Improvements & Equipment 26,853us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BarracksRoad2610CharlottesvilleVAMember
Total 29,829us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BarracksRoad2610CharlottesvilleVAMember
Accumulated Depreciation 13,789us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BarracksRoad2610CharlottesvilleVAMember
491 Crestwood Drive, Charlottesville (4), VA  
Real Estate And Accumulated Depreciation  
Encumbrances 9,889us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrestwoodDrive491CharlottesvilleVAMember
Initial Cost to Company  
Land 641us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrestwoodDrive491CharlottesvilleVAMember
Buildings, Improvements & Equipment 7,633us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrestwoodDrive491CharlottesvilleVAMember
Cost Capitalized Subsequent to Acquisition 926snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrestwoodDrive491CharlottesvilleVAMember
Cost at the end of the period  
Land 641us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrestwoodDrive491CharlottesvilleVAMember
Buildings, Improvements & Equipment 8,559us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrestwoodDrive491CharlottesvilleVAMember
Total 9,200us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrestwoodDrive491CharlottesvilleVAMember
Accumulated Depreciation 2,398us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_CrestwoodDrive491CharlottesvilleVAMember
1005 Elysian Place, Chesapeake, VA  
Initial Cost to Company  
Land 2,370us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElysianPlace1005ChesapeakeVAMember
Buildings, Improvements & Equipment 23,705us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElysianPlace1005ChesapeakeVAMember
Cost Capitalized Subsequent to Acquisition 135snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElysianPlace1005ChesapeakeVAMember
Cost at the end of the period  
Land 2,370us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElysianPlace1005ChesapeakeVAMember
Buildings, Improvements & Equipment 23,840us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElysianPlace1005ChesapeakeVAMember
Total 26,210us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElysianPlace1005ChesapeakeVAMember
Accumulated Depreciation 2,300us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ElysianPlace1005ChesapeakeVAMember
2856 Forehand Drive, Chesapeake, VA  
Initial Cost to Company  
Land 160us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ForehandDrive2856ChesapeakeVAMember
Buildings, Improvements & Equipment 1,498us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ForehandDrive2856ChesapeakeVAMember
Cost Capitalized Subsequent to Acquisition 808snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ForehandDrive2856ChesapeakeVAMember
Cost at the end of the period  
Land 160us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ForehandDrive2856ChesapeakeVAMember
Buildings, Improvements & Equipment 2,306us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ForehandDrive2856ChesapeakeVAMember
Total 2,466us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ForehandDrive2856ChesapeakeVAMember
Accumulated Depreciation 748us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ForehandDrive2856ChesapeakeVAMember
4001 Fair Ridge Drive, Fairfax, VA  
Initial Cost to Company  
Land 2,500us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FairRidgeDrive4001FairfaxVAMember
Buildings, Improvements & Equipment 7,147us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FairRidgeDrive4001FairfaxVAMember
Cost Capitalized Subsequent to Acquisition 443snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FairRidgeDrive4001FairfaxVAMember
Cost at the end of the period  
Land 2,500us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FairRidgeDrive4001FairfaxVAMember
Buildings, Improvements & Equipment 7,590us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FairRidgeDrive4001FairfaxVAMember
Total 10,090us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FairRidgeDrive4001FairfaxVAMember
Accumulated Depreciation 1,280us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_FairRidgeDrive4001FairfaxVAMember
20 HeartFields Lane , Fredericksburg (4), VA  
Real Estate And Accumulated Depreciation  
Encumbrances 10,370us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HeartFieldsLane20FredericksburgVAMember
Initial Cost to Company  
Land 287us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HeartFieldsLane20FredericksburgVAMember
Buildings, Improvements & Equipment 8,480us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HeartFieldsLane20FredericksburgVAMember
Cost Capitalized Subsequent to Acquisition 1,272snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HeartFieldsLane20FredericksburgVAMember
Cost at the end of the period  
Land 287us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HeartFieldsLane20FredericksburgVAMember
Buildings, Improvements & Equipment 9,752us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HeartFieldsLane20FredericksburgVAMember
Total 10,039us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HeartFieldsLane20FredericksburgVAMember
Accumulated Depreciation 3,314us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HeartFieldsLane20FredericksburgVAMember
2800 Polo Parkway, Midlothian, VA  
Initial Cost to Company  
Land 1,103us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PoloParkway2800MidlothianVAMember
Buildings, Improvements & Equipment 13,126us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PoloParkway2800MidlothianVAMember
Cost Capitalized Subsequent to Acquisition 1,428snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PoloParkway2800MidlothianVAMember
Cost at the end of the period  
Land 1,103us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PoloParkway2800MidlothianVAMember
Buildings, Improvements & Equipment 14,554us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PoloParkway2800MidlothianVAMember
Total 15,657us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PoloParkway2800MidlothianVAMember
Accumulated Depreciation 4,076us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_PoloParkway2800MidlothianVAMember
655 Denbigh Boulevard, Newport News (4), VA  
Real Estate And Accumulated Depreciation  
Encumbrances 7,912us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DenbighBoulevard655NewportNewsVAMember
Initial Cost to Company  
Land 581us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DenbighBoulevard655NewportNewsVAMember
Buildings, Improvements & Equipment 6,921us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DenbighBoulevard655NewportNewsVAMember
Cost Capitalized Subsequent to Acquisition 429snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DenbighBoulevard655NewportNewsVAMember
Cost at the end of the period  
Land 581us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DenbighBoulevard655NewportNewsVAMember
Buildings, Improvements & Equipment 7,350us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DenbighBoulevard655NewportNewsVAMember
Total 7,931us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DenbighBoulevard655NewportNewsVAMember
Accumulated Depreciation 2,065us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_DenbighBoulevard655NewportNewsVAMember
6161 Kempsville Rd, Norfolk, VA  
Initial Cost to Company  
Land 1,530us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KempsvilleRd6161NorfolkVAMember
Buildings, Improvements & Equipment 9,531us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KempsvilleRd6161NorfolkVAMember
Cost Capitalized Subsequent to Acquisition 413snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KempsvilleRd6161NorfolkVAMember
Cost at the end of the period  
Land 1,530us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KempsvilleRd6161NorfolkVAMember
Buildings, Improvements & Equipment 9,944us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KempsvilleRd6161NorfolkVAMember
Total 11,474us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KempsvilleRd6161NorfolkVAMember
Accumulated Depreciation 1,512us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KempsvilleRd6161NorfolkVAMember
6311 Granby Street, Norfolk, VA  
Initial Cost to Company  
Land 1,920us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GranbyStreet6311NorfolkVAMember
Buildings, Improvements & Equipment 16,538us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GranbyStreet6311NorfolkVAMember
Cost Capitalized Subsequent to Acquisition 30snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GranbyStreet6311NorfolkVAMember
Cost at the end of the period  
Land 1,920us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GranbyStreet6311NorfolkVAMember
Buildings, Improvements & Equipment 16,568us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GranbyStreet6311NorfolkVAMember
Total 18,488us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GranbyStreet6311NorfolkVAMember
Accumulated Depreciation 1,646us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_GranbyStreet6311NorfolkVAMember
885 Kempsville Rd, Norfolk, VA  
Initial Cost to Company  
Land 1,780us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KempsvilleRd885NorfolkVAMember
Buildings, Improvements & Equipment 8,354us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KempsvilleRd885NorfolkVAMember
Cost Capitalized Subsequent to Acquisition 778snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KempsvilleRd885NorfolkVAMember
Cost at the end of the period  
Land 1,780us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KempsvilleRd885NorfolkVAMember
Buildings, Improvements & Equipment 9,132us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KempsvilleRd885NorfolkVAMember
Total 10,912us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KempsvilleRd885NorfolkVAMember
Accumulated Depreciation 1,418us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KempsvilleRd885NorfolkVAMember
531 Wythe Creek Road, Poquoson, VA  
Initial Cost to Company  
Land 220us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WytheCreekRoad531PoquosonVAMember
Buildings, Improvements & Equipment 2,041us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WytheCreekRoad531PoquosonVAMember
Cost Capitalized Subsequent to Acquisition 740snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WytheCreekRoad531PoquosonVAMember
Cost at the end of the period  
Land 220us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WytheCreekRoad531PoquosonVAMember
Buildings, Improvements & Equipment 2,781us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WytheCreekRoad531PoquosonVAMember
Total 3,001us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WytheCreekRoad531PoquosonVAMember
Accumulated Depreciation 882us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WytheCreekRoad531PoquosonVAMember
3000 Skipwith Road, Richmond, VA  
Initial Cost to Company  
Land 732us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SkipwithRoad3000RichmondVAMember
Buildings, Improvements & Equipment 8,717us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SkipwithRoad3000RichmondVAMember
Cost Capitalized Subsequent to Acquisition 730snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SkipwithRoad3000RichmondVAMember
Cost at the end of the period  
Land 732us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SkipwithRoad3000RichmondVAMember
Buildings, Improvements & Equipment 9,447us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SkipwithRoad3000RichmondVAMember
Total 10,179us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SkipwithRoad3000RichmondVAMember
Accumulated Depreciation 2,616us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SkipwithRoad3000RichmondVAMember
9900 Independence Park Drive, Richmond (4), VA  
Real Estate And Accumulated Depreciation  
Encumbrances 9,205us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IndependenceParkDrive9900RichmondVAMember
Initial Cost to Company  
Land 326us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IndependenceParkDrive9900RichmondVAMember
Buildings, Improvements & Equipment 3,166us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IndependenceParkDrive9900RichmondVAMember
Cost at the end of the period  
Land 326us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IndependenceParkDrive9900RichmondVAMember
Buildings, Improvements & Equipment 3,166us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IndependenceParkDrive9900RichmondVAMember
Total 3,492us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IndependenceParkDrive9900RichmondVAMember
Accumulated Depreciation 244us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IndependenceParkDrive9900RichmondVAMember
9930 Independence Park Drive, Richmond (4), VA  
Initial Cost to Company  
Land 604us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IndependenceParkDrive9930RichmondVAMember
Buildings, Improvements & Equipment 5,432us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IndependenceParkDrive9930RichmondVAMember
Cost at the end of the period  
Land 604us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IndependenceParkDrive9930RichmondVAMember
Buildings, Improvements & Equipment 5,432us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IndependenceParkDrive9930RichmondVAMember
Total 6,036us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IndependenceParkDrive9930RichmondVAMember
Accumulated Depreciation 419us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_IndependenceParkDrive9930RichmondVAMember
5620 Wesleyan Drive, Virginia Beach, VA  
Initial Cost to Company  
Land 893us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WesleyanDrive5620VirginiaBeachVAMember
Buildings, Improvements & Equipment 7,926us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WesleyanDrive5620VirginiaBeachVAMember
Cost Capitalized Subsequent to Acquisition 1,370snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WesleyanDrive5620VirginiaBeachVAMember
Cost at the end of the period  
Land 893us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WesleyanDrive5620VirginiaBeachVAMember
Buildings, Improvements & Equipment 9,296us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WesleyanDrive5620VirginiaBeachVAMember
Total 10,189us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WesleyanDrive5620VirginiaBeachVAMember
Accumulated Depreciation 4,219us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WesleyanDrive5620VirginiaBeachVAMember
4132 Longhill Road, Williamsburg, VA  
Initial Cost to Company  
Land 270us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LonghillRoad4132WilliamsburgVAMember
Buildings, Improvements & Equipment 2,468us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LonghillRoad4132WilliamsburgVAMember
Cost Capitalized Subsequent to Acquisition 943snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LonghillRoad4132WilliamsburgVAMember
Cost at the end of the period  
Land 270us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LonghillRoad4132WilliamsburgVAMember
Buildings, Improvements & Equipment 3,411us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LonghillRoad4132WilliamsburgVAMember
Total 3,681us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LonghillRoad4132WilliamsburgVAMember
Accumulated Depreciation 1,045us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_LonghillRoad4132WilliamsburgVAMember
21717 30th Drive SE, Bothell, WA  
Initial Cost to Company  
Land 3,012us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Drive30thSE21717BothellWAMember
Buildings, Improvements & Equipment 12,582us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Drive30thSE21717BothellWAMember
Cost at the end of the period  
Land 3,012us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Drive30thSE21717BothellWAMember
Buildings, Improvements & Equipment 12,582us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Drive30thSE21717BothellWAMember
Total 15,594us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Drive30thSE21717BothellWAMember
Accumulated Depreciation 603us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Drive30thSE21717BothellWAMember
21823 30th Drive SE, Bothell, WA  
Initial Cost to Company  
Land 2,627us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Drive30thSE21823BothellWAMember
Buildings, Improvements & Equipment 12,657us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Drive30thSE21823BothellWAMember
Cost at the end of the period  
Land 2,629us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Drive30thSE21823BothellWAMember
Buildings, Improvements & Equipment 12,655us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Drive30thSE21823BothellWAMember
Total 15,284us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Drive30thSE21823BothellWAMember
Accumulated Depreciation 606us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Drive30thSE21823BothellWAMember
516 Kenosia Avenue South, Kent (4), WA  
Real Estate And Accumulated Depreciation  
Encumbrances 6,353us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KenosiaAvenueSouth516KentWAMember
Initial Cost to Company  
Land 1,300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KenosiaAvenueSouth516KentWAMember
Buildings, Improvements & Equipment 8,458us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KenosiaAvenueSouth516KentWAMember
Cost Capitalized Subsequent to Acquisition 744snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KenosiaAvenueSouth516KentWAMember
Cost at the end of the period  
Land 1,300us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KenosiaAvenueSouth516KentWAMember
Buildings, Improvements & Equipment 9,202us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KenosiaAvenueSouth516KentWAMember
Total 10,502us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KenosiaAvenueSouth516KentWAMember
Accumulated Depreciation 574us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KenosiaAvenueSouth516KentWAMember
2956 152nd Ave NE, Redmond (4), WA  
Initial Cost to Company  
Land 5,120us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AveNE152nd2956RedmondWAMember
Buildings, Improvements & Equipment 16,683us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AveNE152nd2956RedmondWAMember
Cost Capitalized Subsequent to Acquisition 1,192snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AveNE152nd2956RedmondWAMember
Cost at the end of the period  
Land 5,120us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AveNE152nd2956RedmondWAMember
Buildings, Improvements & Equipment 17,875us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AveNE152nd2956RedmondWAMember
Total 22,995us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AveNE152nd2956RedmondWAMember
Accumulated Depreciation 932us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_AveNE152nd2956RedmondWAMember
555 16th Avenue, Seattle, WA  
Initial Cost to Company  
Land 256us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Avenue16th555SeattleWAMember
Buildings, Improvements & Equipment 4,869us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Avenue16th555SeattleWAMember
Cost Capitalized Subsequent to Acquisition 67snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Avenue16th555SeattleWAMember
Cost at the end of the period  
Land 256us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Avenue16th555SeattleWAMember
Buildings, Improvements & Equipment 4,936us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Avenue16th555SeattleWAMember
Total 5,192us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Avenue16th555SeattleWAMember
Accumulated Depreciation 2,848us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_Avenue16th555SeattleWAMember
18740 W. Bluemound Rd., Brookfield, WI  
Initial Cost to Company  
Land 832us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WBluemoundRd18740BrookfieldWIMember
Buildings, Improvements & Equipment 3,849us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WBluemoundRd18740BrookfieldWIMember
Cost Capitalized Subsequent to Acquisition 4,087snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WBluemoundRd18740BrookfieldWIMember
Cost at the end of the period  
Land 832us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WBluemoundRd18740BrookfieldWIMember
Buildings, Improvements & Equipment 7,936us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WBluemoundRd18740BrookfieldWIMember
Total 8,768us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WBluemoundRd18740BrookfieldWIMember
Accumulated Depreciation 3,649us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WBluemoundRd18740BrookfieldWIMember
3003 West Good Hope Road, Glendale, WI  
Initial Cost to Company  
Land 1,500us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestGoodHopeRoad3003GlendaleWIMember
Buildings, Improvements & Equipment 33,747us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestGoodHopeRoad3003GlendaleWIMember
Cost at the end of the period  
Land 1,500us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestGoodHopeRoad3003GlendaleWIMember
Buildings, Improvements & Equipment 33,747us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestGoodHopeRoad3003GlendaleWIMember
Total 35,247us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestGoodHopeRoad3003GlendaleWIMember
Accumulated Depreciation 4,429us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WestGoodHopeRoad3003GlendaleWIMember
7007 North Range Line Road, Glendale, WI  
Initial Cost to Company  
Land 250us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRangeLineRoad7007GlendaleWIMember
Buildings, Improvements & Equipment 3,797us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRangeLineRoad7007GlendaleWIMember
Cost at the end of the period  
Land 250us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRangeLineRoad7007GlendaleWIMember
Buildings, Improvements & Equipment 3,797us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRangeLineRoad7007GlendaleWIMember
Total 4,047us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRangeLineRoad7007GlendaleWIMember
Accumulated Depreciation 498us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthRangeLineRoad7007GlendaleWIMember
215 Washington Street, Grafton, WI  
Initial Cost to Company  
Land 500us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WashingtonStreet215GraftonWIMember
Buildings, Improvements & Equipment 10,058us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WashingtonStreet215GraftonWIMember
Cost at the end of the period  
Land 500us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WashingtonStreet215GraftonWIMember
Buildings, Improvements & Equipment 10,058us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WashingtonStreet215GraftonWIMember
Total 10,558us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WashingtonStreet215GraftonWIMember
Accumulated Depreciation 1,320us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WashingtonStreet215GraftonWIMember
N168W22022 Main Street, Jackson, WI  
Initial Cost to Company  
Land 188us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MainStreetN168W22022JacksonWIMember
Buildings, Improvements & Equipment 5,962us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MainStreetN168W22022JacksonWIMember
Cost Capitalized Subsequent to Acquisition 5snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MainStreetN168W22022JacksonWIMember
Cost at the end of the period  
Land 188us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MainStreetN168W22022JacksonWIMember
Buildings, Improvements & Equipment 5,967us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MainStreetN168W22022JacksonWIMember
Total 6,155us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MainStreetN168W22022JacksonWIMember
Accumulated Depreciation 6us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_MainStreetN168W22022JacksonWIMember
8351 Sheridan Rd, Kenosha, WI  
Initial Cost to Company  
Land 750us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SheridanRd8351KenoshaWIMember
Buildings, Improvements & Equipment 7,669us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SheridanRd8351KenoshaWIMember
Cost Capitalized Subsequent to Acquisition 148snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SheridanRd8351KenoshaWIMember
Cost at the end of the period  
Land 750us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SheridanRd8351KenoshaWIMember
Buildings, Improvements & Equipment 7,817us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SheridanRd8351KenoshaWIMember
Total 8,567us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SheridanRd8351KenoshaWIMember
Accumulated Depreciation 1,353us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_SheridanRd8351KenoshaWIMember
5601 Burke Rd, Madison, WI  
Initial Cost to Company  
Land 700us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BurkeRd5601MadisonWIMember
Buildings, Improvements & Equipment 7,461us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BurkeRd5601MadisonWIMember
Cost Capitalized Subsequent to Acquisition 51snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BurkeRd5601MadisonWIMember
Cost at the end of the period  
Land 700us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BurkeRd5601MadisonWIMember
Buildings, Improvements & Equipment 7,512us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BurkeRd5601MadisonWIMember
Total 8,212us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BurkeRd5601MadisonWIMember
Accumulated Depreciation 1,306us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_BurkeRd5601MadisonWIMember
7707 N.Brookline Drive, Madison, WI  
Initial Cost to Company  
Land 2,615us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_N.BrooklineDrive7707MadisonWIMember
Buildings, Improvements & Equipment 35,545us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_N.BrooklineDrive7707MadisonWIMember
Cost Capitalized Subsequent to Acquisition 12snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_N.BrooklineDrive7707MadisonWIMember
Cost at the end of the period  
Land 2,615us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_N.BrooklineDrive7707MadisonWIMember
Buildings, Improvements & Equipment 35,557us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_N.BrooklineDrive7707MadisonWIMember
Total 38,172us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_N.BrooklineDrive7707MadisonWIMember
Accumulated Depreciation 38us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_N.BrooklineDrive7707MadisonWIMember
10803 N. Port Washington Rd, Mequon (4), WI  
Real Estate And Accumulated Depreciation  
Encumbrances 4,212us-gaap_RealEstateAndAccumulatedDepreciationAmountOfEncumbrances
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPortWashingtonRd10803MequonWIMember
Initial Cost to Company  
Land 800us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPortWashingtonRd10803MequonWIMember
Buildings, Improvements & Equipment 8,388us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPortWashingtonRd10803MequonWIMember
Cost Capitalized Subsequent to Acquisition 396snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPortWashingtonRd10803MequonWIMember
Cost at the end of the period  
Land 800us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPortWashingtonRd10803MequonWIMember
Buildings, Improvements & Equipment 8,784us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPortWashingtonRd10803MequonWIMember
Total 9,584us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPortWashingtonRd10803MequonWIMember
Accumulated Depreciation 1,557us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NPortWashingtonRd10803MequonWIMember
701 East Puetz Rd, Oak Creek, WI  
Initial Cost to Company  
Land 650us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastPuetzRd701OakCreekWIMember
Buildings, Improvements & Equipment 18,396us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastPuetzRd701OakCreekWIMember
Cost Capitalized Subsequent to Acquisition 262snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastPuetzRd701OakCreekWIMember
Cost at the end of the period  
Land 650us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastPuetzRd701OakCreekWIMember
Buildings, Improvements & Equipment 18,658us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastPuetzRd701OakCreekWIMember
Total 19,308us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastPuetzRd701OakCreekWIMember
Accumulated Depreciation 3,278us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_EastPuetzRd701OakCreekWIMember
321 Riverside Drive, Pewaukee, WI  
Initial Cost to Company  
Land 984us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiversideDrive321PewaukeeWIMember
Buildings, Improvements & Equipment 2,432us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiversideDrive321PewaukeeWIMember
Cost Capitalized Subsequent to Acquisition 1,237snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiversideDrive321PewaukeeWIMember
Cost at the end of the period  
Land 984us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiversideDrive321PewaukeeWIMember
Buildings, Improvements & Equipment 3,669us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiversideDrive321PewaukeeWIMember
Total 4,653us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiversideDrive321PewaukeeWIMember
Accumulated Depreciation 2,018us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_RiversideDrive321PewaukeeWIMember
W231 N1440 Corporate Court, Pewaukee, WI  
Initial Cost to Company  
Land 3,900us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_N1440CorporateCourtW231PewaukeeWIMember
Buildings, Improvements & Equipment 41,140us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_N1440CorporateCourtW231PewaukeeWIMember
Cost at the end of the period  
Land 3,900us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_N1440CorporateCourtW231PewaukeeWIMember
Buildings, Improvements & Equipment 41,140us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_N1440CorporateCourtW231PewaukeeWIMember
Total 45,040us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_N1440CorporateCourtW231PewaukeeWIMember
Accumulated Depreciation 5,400us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_N1440CorporateCourtW231PewaukeeWIMember
8438 & 8400 Washington Avenue, Racine, WI  
Initial Cost to Company  
Land 1,150us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WashingtonAvenue8438And8400RacineWIMember
Buildings, Improvements & Equipment 22,436us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WashingtonAvenue8438And8400RacineWIMember
Cost at the end of the period  
Land 1,150us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WashingtonAvenue8438And8400RacineWIMember
Buildings, Improvements & Equipment 22,436us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WashingtonAvenue8438And8400RacineWIMember
Total 23,586us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WashingtonAvenue8438And8400RacineWIMember
Accumulated Depreciation 2,945us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WashingtonAvenue8438And8400RacineWIMember
1221 North 26th Street, Sheboygan, WI  
Initial Cost to Company  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North26thStreet1221SheboyganWIMember
Buildings, Improvements & Equipment 975us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North26thStreet1221SheboyganWIMember
Cost at the end of the period  
Land 300us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North26thStreet1221SheboyganWIMember
Buildings, Improvements & Equipment 975us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North26thStreet1221SheboyganWIMember
Total 1,275us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North26thStreet1221SheboyganWIMember
Accumulated Depreciation 128us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North26thStreet1221SheboyganWIMember
1222 North 23rd Street, Sheboygan, WI  
Initial Cost to Company  
Land 120us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North23rdStreet1222SheboyganWIMember
Buildings, Improvements & Equipment 4,014us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North23rdStreet1222SheboyganWIMember
Cost at the end of the period  
Land 120us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North23rdStreet1222SheboyganWIMember
Buildings, Improvements & Equipment 4,014us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North23rdStreet1222SheboyganWIMember
Total 4,134us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North23rdStreet1222SheboyganWIMember
Accumulated Depreciation 527us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_North23rdStreet1222SheboyganWIMember
2414 Kohler Memorial Drive, Sheboygan, WI  
Initial Cost to Company  
Land 1,400us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KohlerMemorialDrive2414SheboyganWIMember
Buildings, Improvements & Equipment 35,168us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KohlerMemorialDrive2414SheboyganWIMember
Cost at the end of the period  
Land 1,400us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KohlerMemorialDrive2414SheboyganWIMember
Buildings, Improvements & Equipment 35,168us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KohlerMemorialDrive2414SheboyganWIMember
Total 36,568us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KohlerMemorialDrive2414SheboyganWIMember
Accumulated Depreciation 4,616us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_KohlerMemorialDrive2414SheboyganWIMember
1125 N Edge Trail, Verona, WI  
Initial Cost to Company  
Land 1,365us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NEdgeTrail1125VeronaWIMember
Buildings, Improvements & Equipment 9,581us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NEdgeTrail1125VeronaWIMember
Cost Capitalized Subsequent to Acquisition 889snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NEdgeTrail1125VeronaWIMember
Cost at the end of the period  
Land 1,365us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NEdgeTrail1125VeronaWIMember
Buildings, Improvements & Equipment 10,470us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NEdgeTrail1125VeronaWIMember
Total 11,835us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NEdgeTrail1125VeronaWIMember
Accumulated Depreciation 322us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NEdgeTrail1125VeronaWIMember
1451 Cleveland Avenue, Waukesha, WI  
Initial Cost to Company  
Land 68us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClevelandAvenue1451WaukeshaWIMember
Buildings, Improvements & Equipment 3,452us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClevelandAvenue1451WaukeshaWIMember
Cost Capitalized Subsequent to Acquisition 3,141snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClevelandAvenue1451WaukeshaWIMember
Cost at the end of the period  
Land 68us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClevelandAvenue1451WaukeshaWIMember
Buildings, Improvements & Equipment 6,593us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClevelandAvenue1451WaukeshaWIMember
Total 6,661us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClevelandAvenue1451WaukeshaWIMember
Accumulated Depreciation 3,656us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_ClevelandAvenue1451WaukeshaWIMember
3289 North Mayfair Road, Wauwatosa, WI  
Initial Cost to Company  
Land 2,300us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthMayfairRoad3289WauwatosaWIMember
Buildings, Improvements & Equipment 6,245us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthMayfairRoad3289WauwatosaWIMember
Cost at the end of the period  
Land 2,300us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthMayfairRoad3289WauwatosaWIMember
Buildings, Improvements & Equipment 6,245us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthMayfairRoad3289WauwatosaWIMember
Total 8,545us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthMayfairRoad3289WauwatosaWIMember
Accumulated Depreciation 820us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_NorthMayfairRoad3289WauwatosaWIMember
5301 W. Lincoln Ave, West Allis, WI  
Initial Cost to Company  
Land 1,600us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WLincolnAve5301WestAllisWIMember
Buildings, Improvements & Equipment 20,377us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WLincolnAve5301WestAllisWIMember
Cost Capitalized Subsequent to Acquisition 7,298snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WLincolnAve5301WestAllisWIMember
Cost at the end of the period  
Land 1,600us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WLincolnAve5301WestAllisWIMember
Buildings, Improvements & Equipment 27,675us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WLincolnAve5301WestAllisWIMember
Total 29,275us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WLincolnAve5301WestAllisWIMember
Accumulated Depreciation 3,835us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_WLincolnAve5301WestAllisWIMember
503 South 18th Street, Laramie, WY  
Initial Cost to Company  
Land 191us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South18thStreet503LaramieWYMember
Buildings, Improvements & Equipment 3,632us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South18thStreet503LaramieWYMember
Cost Capitalized Subsequent to Acquisition 793snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South18thStreet503LaramieWYMember
Cost at the end of the period  
Land 191us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South18thStreet503LaramieWYMember
Buildings, Improvements & Equipment 4,425us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South18thStreet503LaramieWYMember
Total 4,616us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South18thStreet503LaramieWYMember
Accumulated Depreciation 2,568us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_South18thStreet503LaramieWYMember
1901 Howell Ave., Worland, WY  
Initial Cost to Company  
Land 132us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HowellAve1901WorlandWYMember
Buildings, Improvements & Equipment 2,507us-gaap_RealEstateAndAccumulatedDepreciationInitialCostOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HowellAve1901WorlandWYMember
Cost Capitalized Subsequent to Acquisition 1,321snh_RealEstateAndAccumulatedDepreciationCostsCapitalizedSubsequentToAcquisition
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HowellAve1901WorlandWYMember
Cost at the end of the period  
Land 132us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfLand
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HowellAve1901WorlandWYMember
Buildings, Improvements & Equipment 3,828us-gaap_RealEstateAndAccumulatedDepreciationCarryingAmountOfBuildingsAndImprovements
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HowellAve1901WorlandWYMember
Total 3,960us-gaap_RealEstateGrossAtCarryingValue
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HowellAve1901WorlandWYMember
Accumulated Depreciation $ 2,009us-gaap_RealEstateAccumulatedDepreciation
/ us-gaap_RealEstateAndAccumulatedDepreciationDescriptionOfPropertyAxis
= snh_HowellAve1901WorlandWYMember