Leases - Lease Cost (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Lease Cost
Amortization of leased assets	$ 1,517	$ 1,344	$ 3,033	$ 2,688
Interest on lease liabilities	2,044	2,217	4,088	4,434
Operating lease cost:	269	272	539	795
Total leased cost	$ 3,830	$ 3,833	$ 7,660	$ 7,917
Weighted-average remaining lease term (in years)
Finance leases	7 years 4 months 17 days		7 years 4 months 17 days		7 years 10 months 9 days
Operating leases	7 years 6 months 25 days		7 years 6 months 25 days		7 years 3 months 7 days
Weighted-average discount rate:
Finance leases	11.05%		11.05%		11.05%
Operating leases	4.68%		4.68%		4.63%