Lease Income - Lease Income (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Leases [Abstract]
Fixed lease payments	$ 702,482	$ 858,587
Variable lease payments	96,040	120,496
Total lease payments	798,522	979,083
Amortization of acquired above and below-market leases	5,901	4,474
Total rental revenue	804,423	983,557	$ 978,574
Loss recognized at commencement, net(1)	(6,237)	0
Interest income(2)	$ 1,817	$ 0