Leases - Rental Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Cash rent	$ 255,996	$ 272,032	$ 778,697	$ 831,931
Straight-line rent	12,595	5,470	18,053	20,925
Lease intangible amortization	(393)	(692)	(1,929)	(2,034)
Property operating cost reimbursements	1,581	1,418	4,372	4,304
Sub-lease	5,175	5,328	15,718	16,099
Total fixed	274,954	283,556	814,911	871,225
Variable	18,585	19,219	55,438	60,008
Income from direct financing leases	153	210	505	638
Total rental revenue	293,692	$ 302,985	870,854	$ 931,871
Rental Revenue [Member]
Lessor, Lease, Description [Line Items]
COVID-19 effect, excluding straight line rent reserve	9,200		13,900
COVID-19 effect, general reserve increase	5,100		6,000
COVID-19 effect, amount not probable For collection	4,100		7,900
COVID-19 effect, straight line rent receivable, increase in reserve	$ 1,000		$ 4,700