Leases - Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Finance lease cost
Amortization of leased assets	$ 4,756	$ 4,199
Interest on lease liabilities	9,488	10,045
Operating lease cost	3,179	4,562
Total lease cost	$ 17,423	$ 18,806
Weighted-average remaining lease term
Finance leases	8 years 10 months 2 days	9 years 9 months 25 days
Operating leases	7 years 4 months 20 days
Weighted-average discount rate:
Finance leases	11.05%	11.05%
Operating leases	5.12%