Leases - Lease Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Interest and Other Income [Abstract]
Fixed income from operating leases	$ 253,911	$ 237,607	$ 507,770	$ 474,830
Variable income from operating leases	58,452	63,590	119,281	120,589
Interest income from direct financing leases	$ 2,150	$ 10,190	$ 5,419	$ 23,714