Lease Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Leases [Abstract]
Rental revenue - fixed payments	$ 176,085	$ 163,516	$ 507,309	$ 481,674
Rental revenue - variable payments (1)	59,306	51,858	173,211	156,772
Rental and related revenue	235,391	$ 215,374	680,520	$ 638,446
Rent Deferrals Granted	8,100		8,100
Operating Lease, Right-of-Use Asset	40,200		40,200		$ 40,500
Finance Lease, Right-of-Use Asset	34,400		34,400
Operating Lease, Liability	43,500		43,500		$ 46,900
Finance Lease, Liability	$ 34,300		$ 34,300