Debt - Interest Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Debt Disclosure [Abstract]
Interest paid on Senior Notes due 2024	$ 2,591	$ 13,513	$ 14,586
Interest paid on Senior Notes due 2029	16,016	0	0
Interest paid on Revolving Credit Facility	2,296	3,165	5,358
Finance Lease, Interest Expense	4,632	3,634	4,150
Amortization of Debt Issuance Costs	1,726	1,525	1,491
Accretion of Silvertip contingent consideration	0	0	396
Interest Expense, Other	303	344	580
Interest Costs Capitalized Adjustment	(11,113)	(1,473)	(1,790)
Interest Costs Incurred	$ 16,451	$ 20,708	$ 24,771