Real Estate Investments - Property Sales (Details)	3 Months Ended				6 Months Ended	9 Months Ended
	Sep. 30, 2020 USD ($)	Mar. 31, 2020 USD ($) property item	Sep. 30, 2019 USD ($)	Jun. 30, 2018 property	Mar. 31, 2020 USD ($)	Sep. 30, 2020 USD ($) item property	Sep. 30, 2019 USD ($) item property	Dec. 31, 2019 USD ($)
Disposals and other
Carrying value	$ 1,108,931,000					$ 1,108,931,000		$ 1,136,816,000
Net Gain	30,000		$ 6,236,000			44,073,000	$ 6,736,000
Impairment charges	941,000					$ 941,000
ALF
Disposals and other
Number of properties sold | property				6
Properties sold
Disposals and other
Number of properties sold | property						21	1
Number of beds or units in property sold | item						2,411	148
Sales price						$ 74,800,000	$ 7,920,000
Carrying value	29,084,000		1,639,000			29,084,000	1,639,000
Net Gain						44,073,000	6,736,000
Net Gain						108,000	$ 500,000
Holdback repayment						90,000
Reassessment adjustment						$ 18,000
Properties sold | SNF | Arizona
Disposals and other
Number of properties sold | property						1
Number of beds or units in property sold | item						194
Sales price						$ 12,550,000
Carrying value	2,229,000					2,229,000
Net Gain						$ 10,292,000
Properties sold | SNF | Colorado
Disposals and other
Number of properties sold | property						3
Number of beds or units in property sold | item						275
Sales price						$ 15,000,000
Carrying value	4,271,000					4,271,000
Net Gain						$ 10,364,000
Properties sold | SNF | Kansas
Disposals and other
Number of properties sold | property						3
Number of beds or units in property sold | item						250
Sales price						$ 9,750,000
Carrying value	7,438,000					7,438,000
Net Gain						$ 1,993,000
Properties sold | SNF | Iowa
Disposals and other
Number of properties sold | property						7
Number of beds or units in property sold | item						544
Sales price						$ 14,500,000
Carrying value	4,886,000					4,886,000
Net Gain						9,029,000
Holdback amount	150,000	$ 838,000			$ 838,000	150,000
Realizable holdback amount		$ 471,000				$ 115,000
Properties sold | SNF | Texas
Disposals and other
Number of properties sold | property						7
Number of beds or units in property sold | item						1,148
Sales price						$ 23,000,000
Carrying value	$ 10,260,000					10,260,000
Net Gain						$ 12,287,000
Properties sold | SNF | Georgia
Disposals and other
Number of properties sold | property							1
Number of beds or units in property sold | item							148
Sales price							$ 7,920,000
Carrying value			$ 1,639,000				1,639,000
Net Gain							$ 6,236,000
Preferred Care, Inc.
Disposals and other
Number of properties sold | property		21
Number of beds or units in property sold | item		2,411
Net Gain		$ 44,073,000			$ 44,000,000