Operating Leases (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($)		Mar. 31, 2019 USD ($)
Property Subject to or Available for Operating Lease [Line Items]
Straight line rent write off	$ 12,500		$ 2,400
Operating Lease, Lease Income	(137,089)	[1]	(134,569)
Property operating expense	13,093		15,551
General and Administrative Expense	$ 10,988		11,710
Number of Properties Subject to Ground Leases	58
Ground Lease Arrangement [Member]
Property Subject to or Available for Operating Lease [Line Items]
Operating Lease, Lease Income	$ (2,046)	[2]	(5,723)
Property operating expense	6,217		5,938
Office Lease [Member]
Property Subject to or Available for Operating Lease [Line Items]
General and Administrative Expense	226		$ 230
straight-line receivable [Member]
Property Subject to or Available for Operating Lease [Line Items]
Straight line rent write off	4,500
Ground Lease Arrangement [Member]
Property Subject to or Available for Operating Lease [Line Items]
Straight line rent write off	$ 8,000

[1] (1) During the three months ended March 31, 2020, the Company wrote-off straight-line receivables of $4.5 million to straight-line rental revenue classified in rental revenue in the accompanying consolidated statements of income and comprehensive income.

[2] (2) During the three months ended March 31, 2020, the Company wrote-off sub-lessor ground lease straight-line receivables $8.0 million to straight-line rental revenue classified in rental revenue in the accompanying consolidated statements of income and comprehensive income. This write-off resulted in a net reduction to total rental revenue related to sublease income on operating ground leases for the three months ended March 31, 2020.