Debt and Other Obligations - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Debt Instrument [Line Items]
Commitment and other fees	$ 415	$ 417
Amortization of deferred financing costs	3,582	3,976
Total	54,809	51,793
Accretion expense	1,052	1,052
8.00% senior secured notes
Debt Instrument [Line Items]
Accretion expense	1,100	1,100
Interest expense	$ 22,200	$ 22,200
8.00% senior secured notes | 8.00% Senior Secured Notes Due 2025
Debt Instrument [Line Items]
Stated interest rate percentage	8.00%	8.00%	8.00%
Interest expense	$ 23,252	$ 23,252
Fixed-rate term loans
Debt Instrument [Line Items]
Interest expense	17,852	9,563
Unsecured term loans | Unsecured term loans
Debt Instrument [Line Items]
Interest expense	339	336
Class A 2015-1 EETC
Debt Instrument [Line Items]
Interest expense	2,612	2,824
Class B 2015-1 EETC
Debt Instrument [Line Items]
Interest expense	442	528
Class C 2015-1 EETC
Debt Instrument [Line Items]
Interest expense	0	777
Class AA 2017-1 EETC
Debt Instrument [Line Items]
Interest expense	1,420	1,521
Class A 2017-1 EETC
Debt Instrument [Line Items]
Interest expense	510	548
Class B 2017-1 EETC
Debt Instrument [Line Items]
Interest expense	445	476
Class C 2017-1 EETC
Debt Instrument [Line Items]
Interest expense	0	522
Convertible notes
Debt Instrument [Line Items]
Convertible notes	3,932	7,045
Convertible notes | Convertible notes due 2026
Debt Instrument [Line Items]
Total	4,400	5,400
Offset of market-to-market adjustment	(500)	1,700
Finance leases
Debt Instrument [Line Items]
Interest expense	$ 8	$ 8