Commitments and Contingencies - Lease Commitments (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020 USD ($) property	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($) property	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Lease Commitments
Properties subject to ground leases | property	23		23
Lease Cost
Fixed lease cost	$ 7,137	$ 7,943	$ 15,146	$ 15,108
Variable lease cost	3,147	4,186	7,087	8,330
Sublease income	(187)	(167)	(373)	(334)
Total operating lease cost	$ 10,097	$ 11,962	21,860	23,104
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases			$ 22,180	$ 24,172
Weighted-average remaining lease term - operating leases	34 years 9 months 18 days	36 years	34 years 9 months 18 days	36 years
Weighted-average discount rate - operating leases	4.86%	4.87%	4.86%	4.87%
Operating Lease Liabilities
2020	$ 32,706		$ 32,706
2021	32,697		32,697
2022	32,721		32,721
2023	32,863		32,863
2024	32,997		32,997
Thereafter	924,243		924,243
Future minimum gross lease payments	1,088,227		1,088,227
Impact of discounting	(568,811)		(568,811)
Operating lease liabilities	$ 519,416		$ 519,416		$ 516,809