Leases - Lease Costs (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)
Finance lease cost:
Amortization of finance lease right-of-use assets	$ 42	$ 126
Interest expense related to finance lease liabilities	73	216
Operating lease cost	7,060	12,737
Variable lease cost	1,624	3,426
Short-term lease cost	28	138
Total lease cost	8,827	16,643
Cash paid for amounts included in the measurement of lease liabilities
Operating cash outflows for finance lease payments	58	173
Operating cash outflows for operating lease payments	6,573	12,122
Total cash flows for lease liability measurement	6,631	12,295
Right-of-use assets obtained in exchange for new operating lease liabilities	52,413	277,430
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 0	$ 8,050
Weighted average remaining lease term - finance leases	47 years 1 month 6 days	47 years 1 month 6 days
Weighted average remaining lease term - operating leases	14 years 10 months 24 days	14 years 10 months 24 days
Weighted average discount rate - operating leases	6.07%	6.07%
Weighted average discount rate - finance leases	3.65%	3.65%