Management Agreements and Leases - Other Net Lease Agreements (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Management Agreements and Leases [Line Items]
Rental income	$ 98,724	$ 96,776	$ 286,742	$ 294,633
Adjustments necessary to record rent on straight line basis	905	2,370	3,087	298
SMTA Transaction
Management Agreements and Leases [Line Items]
Rental income	36,608	34,574	99,594	106,804
Adjustments necessary to record rent on straight line basis	$ 2,361	$ 5,620	$ 11,433	$ 6,702