Commitments and Contingencies - Lease Commitments (Details) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019 USD ($) property	Jun. 30, 2019 USD ($) property
Lease Commitments
Properties subject to ground leases \| property	23	23
Lease Cost
Operating lease cost	$ 7,943	$ 15,108
Variable lease cost	4,186	8,330
Sublease income	(167)	(334)
Total lease cost	11,962	23,104
Lease expense	$ 11,302	23,427
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases		$ 24,172
Weighted-average remaining lease term - operating leases	36 years	36 years
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	(583,181)	(583,181)
Operating lease liabilities	$ 520,593	$ 520,593

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Number of separate real estate development properties located on land subject to ground leases.

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