Operating Leases (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) property state	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) property state	Sep. 30, 2019 USD ($)
Operating Leases
Number of properties owned	6,588		6,588
Number of U.S. states where properties are owned (states) | state	49		49
Percentage rent received | $	$ 532	$ 407	$ 2,300	$ 4,500
Single-tenant properties
Operating Leases
Number of properties owned	6,554		6,554
Single-tenant properties as percentage of total properties	99.50%		99.50%
Properties available for lease or sale
Operating Leases
Number of properties owned	92		92