Commitments and Contingencies - Lease Commitments (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($) property	Sep. 30, 2019 USD ($) property
Lease Commitments
Properties subject to ground leases | property	23	23
Lease Cost
Operating lease cost	$ 7,937	$ 23,045
Variable lease cost	4,183	12,513
Sublease income	(208)	(542)
Total lease cost	11,912	35,016
Lease expense	$ 11,431	34,858
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases		$ 36,268
Weighted-average remaining lease term - operating leases	35 years 9 months 18 days	35 years 9 months 18 days
Weighted-average discount rate - operating leases	4.87%	4.87%
Operating Lease Liabilities
2019	$ 32,444	$ 32,444
2020	32,438	32,438
2021	32,440	32,440
2022	32,451	32,451
2023	32,583	32,583
Thereafter	941,418	941,418
Future minimum gross lease payments	1,103,774	1,103,774
Impact of discounting	(585,162)	(585,162)
Operating lease liabilities	$ 518,612	$ 518,612