Real Estate Properties - Schedule of Disposal Groups (Details) $ in Thousands	1 Months Ended																							12 Months Ended
	Dec. 31, 2020 USD ($) ft² property unit building	Nov. 30, 2020 USD ($) unit building	Oct. 31, 2020 USD ($) unit building	Sep. 30, 2020 USD ($) ft² building	Aug. 31, 2020 USD ($) building unit	Jul. 31, 2020 USD ($) ft² building	Jun. 30, 2020 USD ($) ft² building	Apr. 30, 2020 USD ($) unit building	Mar. 31, 2020 USD ($) ft² building	Feb. 29, 2020 USD ($)	Jan. 31, 2020 USD ($) ft² building	Dec. 31, 2019 USD ($) ft² building unit property	Oct. 31, 2019 USD ($) ft² unit building	Sep. 30, 2019 USD ($) ft² building unit property	Aug. 31, 2019 USD ($) ft² building	Jul. 31, 2019 USD ($) ft² building	Jun. 30, 2019 USD ($) ft² building	May 31, 2019 USD ($) ft² building unit	Mar. 31, 2019 USD ($) ft² building	Feb. 28, 2019 USD ($) ft² building	Jun. 30, 2018 USD ($) unit building	May 31, 2018 USD ($) unit building	Mar. 31, 2018 USD ($) unit building	Dec. 31, 2020 USD ($) ft² property unit building	Dec. 31, 2019 USD ($) ft² building unit property	Dec. 31, 2018 USD ($) building	Feb. 28, 2020 ft² building
Real Estate
Number of Properties | property	397																							397
Gain (loss) on Sale																								$ 6,262
Disposal Group, Disposed of by Sale, Not Discontinued Operations
Real Estate
Number of Properties | building	27											46												27	46	5
Sales Price																								$ 152,893	$ 260,783	$ 334,865
Gain (loss) on Sale																									$ 39,696	$ 261,916
Medical Office
Real Estate
Number of Properties | property	7											20												7	20
Medical Office | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Real Estate
Number of Properties | property	4											13												4	13
Medical Office | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Louisiana
Real Estate
Number of Properties | building											6
Area of real estate properties (in square feet) | ft²											40,575
Sales Price											$ 5,925
Gain (loss) on Sale											$ (81)
Medical Office | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Pennsylvania
Real Estate
Number of Properties | building																											1
Area of real estate properties (in square feet) | ft²																											50,000
Sales Price										$ 2,900
Gain (loss) on Sale										$ 0
Medical Office | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Texas
Real Estate
Number of Properties | building						1			1
Area of real estate properties (in square feet) | ft²						6,849			70,229
Sales Price						$ 2,072			$ 8,779
Gain (loss) on Sale						$ (30)			$ 2,863
Medical Office | Disposal Group, Disposed of by Sale, Not Discontinued Operations | South Carolina
Real Estate
Number of Properties | building							1
Area of real estate properties (in square feet) | ft²							49,242
Sales Price							$ 3,550
Gain (loss) on Sale							$ 0
Medical Office | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Connecticut
Real Estate
Number of Properties | building						1
Area of real estate properties (in square feet) | ft²						32,162
Sales Price						$ 625
Gain (loss) on Sale						$ (25)
Medical Office | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Mississippi
Real Estate
Number of Properties | building				1
Area of real estate properties (in square feet) | ft²				78,747
Sales Price				$ 7,250
Gain (loss) on Sale				$ (114)
Medical Office | Disposal Group, Disposed of by Sale, Not Discontinued Operations | New York
Real Estate
Number of Properties | building	1																							1
Area of real estate properties (in square feet) | ft²	64,060																							64,060
Sales Price	$ 3,875
Gain (loss) on Sale	$ (273)
Medical Office | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Massachusetts
Real Estate
Number of Properties | building														1	1	3	7		1
Area of real estate properties (in square feet) | ft²														41,065	49,357	103,484	164,121		4,400
Sales Price														$ 2,750	$ 2,221	$ 4,955	$ 8,042		$ 75
Gain (loss) on Sale														$ 1,044	$ 812	$ 2,332	$ 1,590		$ (58)
Medical Office | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Colorado
Real Estate
Number of Properties | building																		1
Area of real estate properties (in square feet) | ft²																		15,647
Sales Price																		$ 2,590
Gain (loss) on Sale																		$ 1,029
Medical Office | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Georgia
Real Estate
Number of Properties | building												1													1
Area of real estate properties (in square feet) | ft²												95,010													95,010
Sales Price												$ 14,000
Gain (loss) on Sale												$ (63)
IL / AL | Disposal Group, Disposed of by Sale, Not Discontinued Operations | California
Real Estate
Number of Properties | building								3
Number of units in real estate property | unit								599
Sales Price								$ 47,000
Gain (loss) on Sale								$ (256)
AL | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Mississippi
Real Estate
Number of Properties | building					2
Number of units in real estate property | unit					116
Sales Price					$ 2,500
Gain (loss) on Sale					$ (42)
AL | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Various
Real Estate
Number of Properties | building			3									7													7
Number of units in real estate property | unit			239									566													566
Sales Price			$ 46,000									$ 103,250
Gain (loss) on Sale			$ 4,292									$ 3,593
AL | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Nebraska
Real Estate
Number of Properties | building		1
Number of units in real estate property | unit		131
Sales Price		$ 3,000
Gain (loss) on Sale		$ (26)
AL | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Oregon
Real Estate
Number of Properties | building																					1
Number of units in real estate property | unit																					99
Sales Price																					$ 15,365
Gain (loss) on Sale																					$ (1,793)
Life Science
Real Estate
Number of Properties | property												1													1
Life Science | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Ohio
Real Estate
Number of Properties | building	2																							2
Area of real estate properties (in square feet) | ft²	232,016																							232,016
Sales Price	$ 7,917
Gain (loss) on Sale	$ 257
Life Science | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Florida
Real Estate
Number of Properties | building																				1
Area of real estate properties (in square feet) | ft²																				60,396
Sales Price																				$ 2,900
Gain (loss) on Sale																				$ (69)
Life Science | Disposal Group, Disposed of by Sale, Not Discontinued Operations | New Jersey
Real Estate
Number of Properties | building													1
Area of real estate properties (in square feet) | ft²													205,439
Sales Price													$ 47,500
Gain (loss) on Sale													$ 0
SNF / AL | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Wisconsin
Real Estate
Number of Properties | building	3																							3
Number of units in real estate property | unit	537																							537
Sales Price	$ 11,500
Gain (loss) on Sale	$ (303)
SNF / AL | Disposal Group, Disposed of by Sale, Not Discontinued Operations | South Dakota
Real Estate
Number of Properties | building													3
Number of units in real estate property | unit													245
Sales Price													$ 10,500
Gain (loss) on Sale													$ 6,661
SNF | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Real Estate
Number of Properties | property	8																							8
Number of units in real estate property | property														15
SNF | Disposal Group, Disposed of by Sale, Not Discontinued Operations | California
Real Estate
Number of Properties | building																		3			1
Number of units in real estate property | unit																		278			98
Sales Price																		$ 21,500			$ 6,500
Gain (loss) on Sale																		$ 15,207			$ 3,699
SNF | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Various
Real Estate
Number of Properties | building														15
Number of units in real estate property | unit														964
Sales Price														$ 8,000
Gain (loss) on Sale														$ 0
IL | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Various
Real Estate
Number of Properties | building																							2
Number of units in real estate property | unit																							843
Sales Price																							$ 217,000
Gain (loss) on Sale																							$ 181,154
IL | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Washington
Real Estate
Number of Properties | building												1													1
Number of units in real estate property | unit												150													150
Sales Price												$ 32,500
Gain (loss) on Sale												$ 7,618
IL | Disposal Group, Disposed of by Sale, Not Discontinued Operations | Maryland
Real Estate
Number of Properties | building																						1
Number of units in real estate property | unit																						354
Sales Price																						$ 96,000
Gain (loss) on Sale																						$ 78,856