Additional collateral coverage ratio.

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Calculated collateral coverage ratio.

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Capitalized debt issuance costs, net.

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Debt instrument additional amount borrowed.

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Debt instrument amount borrowed.

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Debt instrument, expiration month and year.

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Debt issuance costs allocated to warrants.

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Discount for balance amount of loans.

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Number of aircraft financed.

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Exercise price per share or per unit of warrants or rights outstanding.

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Number of securities into which the class of warrant or right may be converted. For example, but not limited to, 500,000 warrants may be converted into 1,000,000 shares.

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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No definition available.

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The reference rate for the variable rate of the debt instrument, such as LIBOR or the US Treasury rate and the maturity of the reference rate used, such as three months or six months LIBOR.

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Face (par) amount of debt instrument at time of issuance.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Amount, after accumulated amortization, of debt discount.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Cash payments for and related to principal collection on loans related to operating activities.

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The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer.

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Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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Long-Term Debt, Financing Leases and Other Borrowings - Additional Information (Detail)					3 Months Ended
	Nov. 13, 2020 USD ($)	Nov. 12, 2020 USD ($) Air-craft	Oct. 30, 2020 USD ($) $ / shares shares	Sep. 25, 2019 USD ($)	Dec. 31, 2020 USD ($) $ / shares	Jun. 30, 2020 USD ($)	Nov. 14, 2020 USD ($)	Sep. 30, 2020 USD ($)	Apr. 09, 2020 $ / shares
Debt Instrument [Line Items]
Property and equipment, net					$ 1,194,061,000			$ 1,212,415,000
Long-Term Debt					723,861,000			$ 731,724,000
Proceeds from long-term debt					$ 195,000,000
Warrants of common stock exercise price \| $ / shares					$ 0.004				$ 3.98
Maximum [Member]
Debt Instrument [Line Items]
Calculated collateral coverage ratio			1.6
Minimum [Member]
Debt Instrument [Line Items]
Additional collateral coverage ratio			1.6
Loan Agreement [Member]
Debt Instrument [Line Items]
Secured term loan facility, amount borrowed			$ 43,000,000
Secured term loan facility, additional amount borrowed	$ 152,000,000
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					$ 100,000
Repayments of long term debt		$ 167,700,000
Number of aircraft financed \| Air-craft		44
Loan Agreement [Member] \| $43M Treasury Loan [Member]
Debt Instrument [Line Items]
Capitalized debt issuance costs, net			$ 700,000
Loan Agreement [Member] \| $152M Treasury Loan [Member]
Debt Instrument [Line Items]
Capitalized debt issuance costs, net	2,300,000
Loan Agreement [Member] \| EDC Loans [Member]
Debt Instrument [Line Items]
Debt issuance costs	3,100,000
Repayments of long term debt	1,000,000.0
Payment of loans		$ 164,100,000
Discount for balance amount of loans		$ 3,600,000
Debt discount	2,500,000
Equipment Notes [Member]
Debt Instrument [Line Items]
Long-Term Debt					$ 172,100,000
Working Capital Draw Loan [Member] \| Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Debt instrument, face amount				$ 35,000,000.0
Term loan, term				3 years
Debt instrument, expiration year and month				2022-09
Long term debt interest rate description					one-month LIBOR plus 3.75%
Proceeds from long-term debt						$ 23,000,000.0
Working Capital Draw Loan [Member] \| Revolving Credit Facility [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Long term debt, basis spread on variable rate				3.75%
Secured Term Loan Facility [Member] \| Loan Agreement [Member]
Debt Instrument [Line Items]
Long term debt interest rate description					three-month LIBOR plus 3.50%
Long term debt, basis spread on variable rate			3.50%
Secured term loan facility, maximum borrowing capacity			$ 200,000,000.0
Secured term loan facility, amount borrowed			$ 43,000,000.0
Secured term loan facility, additional amount borrowed	152,000,000.0						$ 0
Debt instrument, maturity date			Oct. 30, 2025		Oct. 30, 2025
Secured Term Loan Facility [Member] \| Loan Agreement [Member] \| $43M Treasury Loan [Member]
Debt Instrument [Line Items]
Secured term loan facility, amount borrowed			$ 43,000,000.0
Secured Term Loan Facility [Member] \| Loan Agreement [Member] \| $152M Treasury Loan [Member]
Debt Instrument [Line Items]
Secured term loan facility, additional amount borrowed	$ 152,000,000.0						$ 0
Aircraft and Equipment [Member] \| Pledged as Collateral [Member]
Debt Instrument [Line Items]
Property and equipment, net					$ 1,077,000,000.0