Debt - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Debt Disclosure [Abstract]
Interest paid on Senior Notes due 2024	$ 2,591	$ 3,378
Interest paid on Senior Notes due 2029	1,602	0
Interest paid on Revolving Credit Facility	480	549
Finance Lease, Interest Expense	589	1,005
Amortization of Debt Issuance Costs	404	381
Interest Expense, Other	57	35
Interest Costs Capitalized Adjustment	(813)	(220)
Interest Costs Incurred	$ 4,910	$ 5,128