Leases - Minimum Annual Rental Payments Under Operating Leases (Details) $ in Thousands	Jun. 30, 2019 USD ($)
Lessee Lease Description [Line Items]
July 1, 2019 to December 31, 2019	$ 2,640
2020	5,156
2021	5,143
2022	5,053
2023	4,363
Thereafter	432,813
Total	455,168
Less: minimum payments for leases not yet commenced	(17,849)
Less: discount	(356,512)
Total lease liability	$ 80,807
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesAndOtherLiabilities
Office Lease Future Minimum Rent
Lessee Lease Description [Line Items]
July 1, 2019 to December 31, 2019	$ 1,583
2020	2,806
2021	2,704
2022	2,561
2023	1,871
Thereafter	10,644
Total	22,169
Less: minimum payments for leases not yet commenced	(17,849)
Less: discount	(308)
Total lease liability	$ 4,012
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesAndOtherLiabilities
Ground Lease Future Minimum Rent
Lessee Lease Description [Line Items]
July 1, 2019 to December 31, 2019	$ 1,057
2020	2,350
2021	2,439
2022	2,492
2023	2,492
Thereafter	422,169
Total	432,999
Less: discount	(356,204)
Total lease liability	$ 76,795
Operating Lease, Liability, Statement of Financial Position [Extensible List]	us-gaap:AccruedLiabilitiesAndOtherLiabilities