Real Estate Investments, Net - Rental Income (Details)	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) state	Sep. 30, 2019 USD ($) operator	Sep. 30, 2020 USD ($) state	Sep. 30, 2019 USD ($) operator
Lessor, Lease, Description [Line Items]
Contractual rent due	$ 42,866,000	$ 43,109,000	$ 127,789,000	$ 124,642,000
Straight-line rent	17,000	546,000	65,000	1,483,000
Adjustment for collectibility	0	(12,078,000)	0	(12,078,000)
Recovery of previously reserved rent	1,047,000	0	1,047,000	0
Lease termination revenue	1,106,000	0	1,106,000	0
Total rental income	$ 45,036,000	$ 31,577,000	$ 130,007,000	$ 114,047,000
Number of operators for which collectability not probable | operator		5		5
Number of operators for which rental revenue was recovered after previous write off | state	1		1
Contractual Rent
Lessor, Lease, Description [Line Items]
Adjustment for collectibility		$ (7,800,000)		$ (7,800,000)
Straight-line rent
Lessor, Lease, Description [Line Items]
Adjustment for collectibility		(3,500,000)		(3,500,000)
Property taxes
Lessor, Lease, Description [Line Items]
Adjustment for collectibility		$ (800,000)		$ (800,000)