Debt and Letters of Credit - Schedule of Debt (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Current:
Other borrowings	$ 911	$ 4,890
Long-term:
Borrowings under credit facility	0	0
Long-term debt	1,167,366	1,701,098
Total long-term	1,167,366	1,701,098
2023 Notes
Long-term:
Long-term debt	193,012	611,250
Unamortized discount	(49)	(283)
Unamortized deferred financing costs	(211)	(1,203)
2024 Notes
Long-term:
Long-term debt	381,014	500,000
Unamortized discount	(1,214)	(2,130)
Unamortized deferred financing costs	(951)	(1,670)
2028 Notes
Long-term:
Long-term debt	600,000	600,000
Unamortized discount	(854)	(981)
Unamortized deferred financing costs	$ (3,381)	$ (3,885)