Schedule IV - Mortgage Loans on Real Estate Schedule IV - Mortgage Loans on Real Estate (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 202,877	$ 98,110	$ 99,179	$ 101,124
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Principal Amount of Delinquent Loans	$ 0
Construction Loans [Member] | Phoenix, AZ [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	7.30%
Mortgage Loans on Real Estate, Final Maturity Date	Dec. 31, 2028
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Periodic Payment Terms, Description	Interest Only
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	$ 76,653
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 75,465
Skilled Nursing Facility [Member] | First Mortgage [Member] | Virginia Beach, VA [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	8.00%
Mortgage Loans on Real Estate, Final Maturity Date	Dec. 31, 2031
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Periodic Payment Terms, Description	31000
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	$ 3,814
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 2,427
Skilled Nursing Facility [Member] | First Mortgage [Member] | Lexington, VA [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	8.00%
Mortgage Loans on Real Estate, Final Maturity Date	Dec. 31, 2032
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Periodic Payment Terms, Description	21000
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	$ 3,089
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 1,758
Skilled Nursing Facility [Member] | First Mortgage [Member] | Brookneal, VA [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	8.00%
Mortgage Loans on Real Estate, Final Maturity Date	Dec. 31, 2031
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Periodic Payment Terms, Description	21000
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	$ 2,780
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 1,716
Skilled Nursing Facility [Member] | First Mortgage [Member] | Laurel Fork, VA [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	8.00%
Mortgage Loans on Real Estate, Final Maturity Date	Dec. 31, 2030
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Periodic Payment Terms, Description	20000
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	$ 2,672
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 1,620
Assisted Living Facility [Member] | First Mortgage [Member] | Oviedo, FL [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	8.25%
Mortgage Loans on Real Estate, Final Maturity Date	Dec. 31, 2021
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Periodic Payment Terms, Description	Interest Only
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	$ 10,000
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 10,000
Assisted Living Facility [Member] | First Mortgage [Member] | Rye, NH [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	8.00%
Mortgage Loans on Real Estate, Final Maturity Date	Dec. 31, 2022
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Periodic Payment Terms, Description	Interest Only
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	$ 10,000
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 9,928
Assisted Living Facility [Member] | Construction Loans [Member] | Virginia Beach, VA [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	9.00%
Mortgage Loans on Real Estate, Final Maturity Date	Dec. 31, 2023
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Periodic Payment Terms, Description	Interest Only
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	$ 4,515
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 4,515
Assisted Living Facility [Member] | Construction Loans [Member] | Phoenix, AZ [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	8.50%
Mortgage Loans on Real Estate, Final Maturity Date	Dec. 31, 2023
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Periodic Payment Terms, Description	Interest Only
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	$ 10,165
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 9,553
Assisted Living Facility [Member] | Construction Loans [Member] | Gurnee, IL [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	9.00%
Mortgage Loans on Real Estate, Final Maturity Date	Dec. 31, 2021
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Periodic Payment Terms, Description	Interest Only
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	$ 13,047
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 13,047
Assisted Living Facility [Member] | Construction Loans [Member] | Canton, MI [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	9.00%
Mortgage Loans on Real Estate, Final Maturity Date	Dec. 31, 2023
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Periodic Payment Terms, Description	Interest Only
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	$ 2,978
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 2,978
Assisted Living Facility [Member] | Construction Loans [Member] | Shelby Township, MI [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	9.00%
Mortgage Loans on Real Estate, Final Maturity Date	Dec. 31, 2022
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Periodic Payment Terms, Description	Interest Only
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	$ 11,931
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 11,931
Entrance-Fee Communities [Member] | First Mortgage [Member] | Issaquah, WA [Member]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate [Line Items]
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Interest Rate	6.75%
Mortgage Loans on Real Estate, Final Maturity Date	Dec. 31, 2025
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate, Periodic Payment Terms, Description	Interest Only
Mortgage Loans on Real Estate, Carrying Amount of Mortgages	$ 57,939
SEC Schedule, 12-29, Real Estate Companies, Investment in Mortgage Loans on Real Estate	$ 57,939