Commitments and Contingencies - Lease Commitments (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) property	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Lease Commitments
Properties subject to ground leases | property	23
Lease Cost
Fixed lease cost	$ 8,009	$ 7,165
Variable lease cost	3,940	4,144
Sublease income	(186)	(167)
Total operating lease cost	11,763	11,142
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$ 11,923	$ 12,068
Weighted-average remaining lease term - operating leases	35 years 1 month 6 days	36 years 2 months 12 days
Weighted-average discount rate - operating leases	4.86%	4.87%
Operating Lease Liabilities
2020	$ 32,706
2021	32,697
2022	32,721
2023	32,863
2024	32,997
Thereafter	923,246
Future minimum gross lease payments	1,087,230
Impact of discounting	(565,852)
Operating lease liabilities	$ 521,378		$ 516,809