Leases - Schedule of Future Lease Payments Due Under Ground Leases (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Operating Leases
2019 (remaining)	$ 990
2020	3,879
2021	3,982
2022	4,093
2023	4,134
2024	4,305
Thereafter	594,510
Total undiscounted future lease payments	615,893
Difference between undiscounted cash flows and discounted cash flows	(536,622)
Total lease liability	79,271
Financing Leases
2019 (remaining)	737
2020	2,991
2021	3,081
2022	3,174
2023	3,269
2024	3,367
Thereafter	330,548
Total undiscounted future lease payments	347,167
Difference between undiscounted cash flows and discounted cash flows	(290,653)
Total lease liability	$ 56,514	$ 4,300