Debt and Other Obligations - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Debt Instrument [Line Items]
Commitment and other fees	$ 412	$ 418	$ 827	$ 955
Amortization of deferred financing costs	3,853	3,210	7,829	7,432
Total	28,880	30,124	80,674	68,004
Accretion expense			2,105	521
Amortization of debt discount			2,378	6,346
8.00% senior secured notes due 2025
Debt Instrument [Line Items]
Accretion expense	1,100	300	2,100	500
Interest expense	$ 22,200	$ 10,200	$ 44,400	$ 20,400
8.00% senior secured notes due 2025 | 8.00% Senior Secured Notes Due 2025
Debt Instrument [Line Items]
Stated interest rate percentage	8.00%	8.00%	8.00%	8.00%	8.00%
Interest expense	$ 23,252	$ 10,461	$ 46,505	$ 20,921
Fixed-rate term loans
Debt Instrument [Line Items]
Interest expense	9,339	10,485	18,901	21,169
Unsecured term loans | Unsecured term loans
Debt Instrument [Line Items]
Interest expense	340	340	676	676
Class A 2015-1 EETC
Debt Instrument [Line Items]
Interest expense	2,730	2,954	5,554	6,001
Class B 2015-1 EETC
Debt Instrument [Line Items]
Interest expense	487	575	1,015	1,191
Class C 2015-1 EETC
Debt Instrument [Line Items]
Interest expense	0	856	777	1,773
Class AA 2017-1 EETC
Debt Instrument [Line Items]
Interest expense	1,521	1,640	3,042	3,278
Class A 2017-1 EETC
Debt Instrument [Line Items]
Interest expense	548	591	1,097	1,182
Class B 2017-1 EETC
Debt Instrument [Line Items]
Interest expense	477	510	953	1,022
Class C 2017-1 EETC
Debt Instrument [Line Items]
Interest expense	0	1,092	522	2,171
Convertible Notes
Debt Instrument [Line Items]
Interest expense, net of adjustments	(14,087)	(3,024)	(7,041)	199
Convertible Notes | Convertible notes due 2026
Debt Instrument [Line Items]
Total	100	5,400	5,500	9,500
Offset of market-to-market adjustment	14,200	8,400	12,500	9,300
Finance leases
Debt Instrument [Line Items]
Interest expense	$ 8	$ 16	$ 17	$ 34