Operating Leases (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($) property state	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) property state	Jun. 30, 2020 USD ($)
Operating Leases
Number of properties owned	6,761		6,761
Number of U.S. states where operating | state	50		50
Percentage rent received | $	$ 596	$ 547	$ 1,600	$ 1,800
Single-client properties
Operating Leases
Number of properties owned	6,715		6,715
Single-client properties as percentage of total properties	99.30%		99.30%
Properties available for lease or sale
Operating Leases
Number of properties owned	103		103