Lease Commitments and Contingencies - Lease Cost and Related Supplemental Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease expense	$ 2,797	$ 5,623
Variable lease expense	173	1,579
Short-term lease expense	2,205	6,635
Sublease income	0	(244)
Total lease cost	$ 5,175	$ 13,593
Weighted-average remaining lease term	16 years 9 months 18 days	16 years 8 months 12 days
Weighted-average discount rate	4.10%	4.20%
Operating cash flows for operating leases	$ 2,679	$ 5,494
Leased assets obtained in exchange for new operating lease liabilities (non-cash activity)	$ 1,769	$ 5,512