Long-Term Debt, Finance Leases, and Other Borrowings - Additional Information (Detail) $ / shares in Units, $ in Thousands											1 Months Ended	12 Months Ended
	Jan. 11, 2024 USD ($) AirCraft	Dec. 31, 2023 USD ($)	Dec. 01, 2023 USD ($)	Oct. 01, 2023 USD ($) Engine AirCraft	Sep. 06, 2023 USD ($)	Dec. 27, 2022 USD ($)	Dec. 31, 2021 USD ($)	Nov. 13, 2020 USD ($)	Nov. 12, 2020 USD ($) AirCraft	Oct. 30, 2020 USD ($) $ / shares shares	May 31, 2023 AirCraft	Sep. 30, 2023 USD ($) AirCraft $ / shares	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Nov. 14, 2020 USD ($)	Jun. 30, 2015 AirCraft
Debt Instrument [Line Items]
Property and equipment, net												$ 698,022	$ 865,254
Long-Term Debt												528,278	599,735
Debt outstanding												$ 538,274	615,310
Warrants of common stock exercise price | $ / shares												$ 3.98
Loan forgiven												$ (1,505)	$ (397)	$ 950
Principal payments												$ 22,200
Subsequent Event [Member]
Debt Instrument [Line Items]
Number of aircraft sold | AirCraft	4
Gross proceeds from sale of asset			$ 56,000	$ 56,000
CRJ-900 Aircraft [Member]
Debt Instrument [Line Items]
Number of aircraft classified as assets held for sale | AirCraft												14
Number of aircraft sold | AirCraft												7
CRJ-900 Aircraft [Member] | American Airlines Inc. [Member]
Debt Instrument [Line Items]
Gross proceeds from sale of asset												$ 29,700
CRJ-900 Aircraft [Member] | American Airlines Inc. [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Number of aircraft sold | AirCraft				4
Gross proceeds from sale of asset				$ 41,500
Treasury Loan [Member]
Debt Instrument [Line Items]
Debt outstanding												139,100
Principal payments												65,800
Treasury Loan [Member] | Maximum [Member]
Debt Instrument [Line Items]
Calculated collateral coverage ratio										0.155
Treasury Loan [Member] | Minimum [Member]
Debt Instrument [Line Items]
Additional collateral coverage ratio										0.155
EDC Loan and MHIRJ Junior Note [Member]
Debt Instrument [Line Items]
Debt outstanding												39,000
Gross proceeds from sale of asset												$ 27,200
EDC Loan and MHIRJ Junior Note [Member] | American Airlines Inc. [Member]
Debt Instrument [Line Items]
Number of aircraft held for sale | AirCraft											7
Number of aircraft sold | AirCraft												3
EDC Loan and MHIRJ Junior Note [Member] | American Airlines Inc. [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Number of aircraft sold | AirCraft				4
EDC Loan and MHIRJ Junior Note [Member] | CRJ-900 Aircraft [Member]
Debt Instrument [Line Items]
Debt instrument, maturity date												Jun. 30, 2027
Number of aircraft financed | AirCraft																7
Deferred loan amount outstanding												$ 14,000
EDC Loan and MHIRJ Junior Note [Member] | CRJ-900 Aircraft [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Repayments of long term debt				$ 4,200
Loan forgiven				$ 5,000
EDC Loan and MHIRJ Junior Note [Member] | CRJ-900 Aircraft [Member] | Scenario Forecast [Member]
Debt Instrument [Line Items]
Repayments of long term debt		$ 4,200
Loan forgiven		$ 5,000
Loan Agreement [Member]
Debt Instrument [Line Items]
Secured term loan facility, amount borrowed										$ 43,000
Secured term loan facility, additional amount borrowed								$ 152,000
Warrants to purchase shares of common stock | shares										4,899,497
Warrants of common stock exercise price | $ / shares										$ 3.98
Debt issuance costs allocated to warrants												100
Repayments of long term debt									$ 167,700
Number of aircraft financed | AirCraft									44
Loan Agreement [Member] | EDC Loans [Member]
Debt Instrument [Line Items]
Debt issuance costs								3,100
Repayments of long term debt								1,000
Payment of loans									$ 164,200
Discount for balance amount of loans									$ 3,500
Unamortized debt discounts								2,500
Loan Agreement [Member] | FortyThreeMillionTreasuryLoanMember
Debt Instrument [Line Items]
Capitalized debt issuance costs, net										$ 700
Loan Agreement [Member] | $152M Treasury Loan [Member]
Debt Instrument [Line Items]
Capitalized debt issuance costs, net								2,300
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Permitted amount to redraw from existing credit facility					$ 7,900
Revolving Credit Facility [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Repayments of long term debt	$ 2,100
Revolving Credit Facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Revolving commitments					50,700
Revolving Credit Facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
Revolving commitments					$ 30,700
Spare Engine Facility [Member] | Loan Agreement [Member]
Debt Instrument [Line Items]
Secured term loan facility, maximum borrowing capacity							$ 54,000
Debt instrument, maturity date							Dec. 31, 2027
Debt instrument, face amount							$ 35,300
Long term debt interest rate description													LIBOR plus 4.25%
Long term debt, basis spread on variable rate							4.25%
Spare Engine Facility [Member] | Loan Agreement [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Number of new spare engines to be acquired | Engine				12
Equipment Notes [Member]
Debt Instrument [Line Items]
Long-Term Debt												108,800
Secured Term Loan Facility [Member] | Loan Agreement [Member]
Debt Instrument [Line Items]
Secured term loan facility, maximum borrowing capacity										200,000
Secured Term Loan Facility [Member] | Loan Agreement [Member] | Treasury Loan [Member]
Debt Instrument [Line Items]
Secured term loan facility, amount borrowed										$ 43,000
Secured term loan facility, additional amount borrowed								$ 152,000							$ 0
Debt instrument, maturity date										Oct. 30, 2025
Long term debt, basis spread on variable rate										3.50%
American Capacity Purchase Agreement [Member] | EDC Loan and MHIRJ Junior Note [Member]
Debt Instrument [Line Items]
Repayment of senior and junior notes												$ 34,600
American Purchase Agreement [Member] | CRJ-900 Aircraft [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Number of aircraft sold | AirCraft				4
Gross proceeds from sale of asset				$ 41,500
American Purchase Agreement [Member] | EDC Loan and MHIRJ Junior Note [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Gross proceeds from sale of asset				600
American Purchase Agreement [Member] | EDC Loan and MHIRJ Junior Note [Member] | CRJ-900 Aircraft [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Repayments of long term debt				4,200
Loan forgiven				$ 5,000
United Capacity Purchase Agreement [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Repayments of long term debt	$ 10,500
United Capacity Purchase Agreement [Member] | United Airlines, Inc. [Member]
Debt Instrument [Line Items]
Percentage of controllable completion factor												99.30%
United Capacity Purchase Agreement [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long term debt, basis spread on variable rate					3.50%	3.50%
Long-Term Line of Credit						$ 10,500
Revolving commitments						30,700
Covenant capping restricted payments						$ 5,000
Rental coverage ratio						1
United Capacity Purchase Agreement [Member] | Revolving Credit Facility [Member] | SOFR [Member]
Debt Instrument [Line Items]
Long term debt, basis spread on variable rate					4.50%	4.50%
United Capacity Purchase Agreement [Member] | Revolving Credit Facility [Member] | United Airlines, Inc. [Member]
Debt Instrument [Line Items]
Letter of credit facility, amount												$ 25,500
Additional prepayment with potential forgiveness												15,000
Forgiveness achieved												9,000
United Capacity Purchase Agreement [Member] | Revolving Credit Facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
Amount required						$ 15,000
Aircraft and Equipment [Member] | Pledged as Collateral [Member]
Debt Instrument [Line Items]
Property and equipment, net												$ 660,400