Leases - Lease Cost, Weighted Average Term, Discount Rates and Cash Flows (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Lease cost
Operating lease cost	$ 5,867
Finance lease cost:
Amortization of right-of-use assets	20,666
Interest on lease liabilities	6,018
Short-term lease cost	120
Variable lease cost	1,970
Total lease cost	$ 34,641
Weighted average remaining lease term (in years):
Finance leases	4 years 9 months 25 days
Operating leases	10 years 3 months 7 days
Weighted average discount rate:
Finance leases	10.75%
Operating leases	6.19%
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows from operating leases	$ 5,371
Operating cash flows from finance leases	6,018
Financing cash flows from finance leases	9,758
Right-of-use asset obtained in exchange for lease liability	$ 1,000