Combined Guarantor Subsidiaries - Leases - Components of Rental Revenue (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Lessor Lease Description [Line Items]
Fixed lease payments	$ 99,150,000	$ 151,730,000	$ 236,544,000	$ 311,002,000
Variable lease payments	21,072,000	33,663,000	44,851,000	65,371,000
Total rental revenues	120,222,000	185,393,000	281,395,000	376,373,000
Guarantor Subsidiaries
Lessor Lease Description [Line Items]
Fixed lease payments	37,096,000	54,755,000	91,751,000	115,062,000
Variable lease payments	9,753,000	12,561,000	18,929,000	23,526,000
Total rental revenues	$ 46,849,000	$ 67,316,000	$ 110,680,000	$ 138,588,000