Real Estate Investments - Operator changes (Details)				3 Months Ended			12 Months Ended
	Jun. 01, 2020 USD ($)	Aug. 01, 2019 USD ($) item	Jun. 01, 2019 USD ($)	Dec. 31, 2019 USD ($) property contract	Sep. 30, 2019 USD ($) item	Jun. 30, 2019 USD ($) item	Dec. 31, 2019 USD ($) property	Dec. 31, 2017 property	Dec. 31, 2018 property
Other disclosures
Rental income							$ 152,755,000
Number of completed contracts | contract				2
Number of properties held for sale | property				20			20
Court ordered payment amount							$ 1,596,000
Rent in year two				$ 126,914,000			126,914,000
Rent in year three				128,196,000			128,196,000
Rent in year four				$ 129,846,000			$ 129,846,000
Arizona and Texas
Other disclosures
Number of properties sold | property				2
Georgia and South Carolina
Other disclosures
Rent on cash basis					$ 1,762,000
Florida
Other disclosures
Increase in Lease Rent (as a percent)					3.50%
Properties held-for-sale
Other disclosures
Number of properties | property				20			20		1
Anthem Memory Care
Other disclosures
Number of properties in default | property								11
Minimum cash rent received							$ 7,500,000
Percentage of contractual amount due							50.00%
Preferred Care, Inc.
Other disclosures
Minimum cash rent received					$ 55,000
Number of properties under two master leases | property								24
Rental income				$ 55,000
Minimum cash rent receivable					$ 1,000,000
Thrive
Other disclosures
Initial lease term					2 years	10 years
Number of properties in transition | item						2
Rent in year one						$ 1,250,000
Rent in year two						1,500,000
Rent in year three						1,975,000
Rent in year four						$ 2,150,000
Rent on cash basis							$ 700,000
Master lease in default
Other disclosures
Increase in Lease Rent			$ 400,000
Master lease in default | Forecast
Other disclosures
Increase in Lease Rent	$ 300,000
Increase in Lease Rent (as a percent)	2.50%
ALF and MC | Thrive
Other disclosures
Number of properties in transition | item					2
120 units | MC | Thrive | Ohio and Kentucky
Other disclosures
Number of properties in transition | item						120
56-unit MC | Texas
Other disclosures
Number of properties in transition | item						56
159 units | Georgia and South Carolina
Other disclosures
Number of properties in transition | item					159
60-unit MC | Florida
Other disclosures
Initial lease term		10 years
Number of properties in transition | item		60
Rent in year two		$ 450,000
Rent in year three		600,000
60-unit MC | Maximum | Florida
Other disclosures
Deferred lease payments		$ 150,000