Leases - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Lease Liabilities, Payments Due [Abstract]
Year 1	$ 5,738
Year 2	5,947
Year 3	5,735
Year 4	5,867
Year 5	5,641
Years thereafter	578,442
Total future minimum lease payments	607,370
Less amount representing interest	(503,105)
Total present value of minimum payments	104,265	$ 100,900
Finance Lease Liabilities, Payments, Due [Abstract]
Year 1	244
Year 2	244
Year 3	235
Year 4	218
Year 5	161
Years thereafter	635
Total future minimum lease payments	1,737
Less amount representing interest	(336)
Total present value of minimum payments	$ 1,401		$ 618