Rental Income - Lease Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Leases [Abstract]
Fixed lease payments	$ 171,866	$ 214,282	$ 538,601	$ 641,007
Variable lease payments	21,979	32,581	70,892	88,539
Total lease payments	193,845	246,863	609,493	729,546
Amortization of acquired above and below-market leases	1,670	1,165	4,539	3,559
Total rental revenue	195,515	248,028	614,032	733,105
Loss recognized at commencement, net(1)	(5,973)	0	(5,973)	0
Interest income(2)	484	0	484	0
Total loss recognized on sales-type leases	$ (5,489)	$ 0	$ (5,489)	$ 0