Leases - Lease Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lease Cost
Operating lease cost	$ 12,085	$ 12,259
Sublease income	(1,434)	(1,508)
Short-term lease cost	5,959	6,495
Total lease cost	16,610	17,246
Operating cash flows from operating leases	$ 8,520	$ 8,507
Weighted-average remaining lease term in years - operating leases	7 years 4 months 24 days	8 years 4 months 24 days
Weighted-average discount rate - operating leases	6.30%	6.30%
Taxes, insurance and maintenance related to operating lease	$ 3,600	$ 3,700