Goods and services credit.

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Number of aircraft financed.

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Number of aircraft purchased.

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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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Decrease for amounts of indebtedness forgiven by the holder of the debt instrument.

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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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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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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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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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The loss recognized on termination of a contract.

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The cash outflow for acquisition of long-lived depreciable flight assets, including owned aircraft or capital improvements.

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Amount of cash outflow for cost from early extinguishment and prepayment of debt. Includes, but is not limited to, third-party cost, premium paid, and other fee paid to lender directly for debt extinguishment or debt prepayment. Excludes accrued interest.

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The net cash inflow or outflow in aggregate debt due to repayments and proceeds from additional borrowings.

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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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Amount of cash outflow for payment of an obligation from a lender, including but not limited to, letter of credit, standby letter of credit and revolving credit arrangements.

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Amount of a short-term obligation that has been excluded from current liabilities in the balance sheet because of a refinancing of the obligation.

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Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

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Long-Term Debt and Other Borrowings - Additional Information (Detail) $ in Thousands						1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 14, 2019 USD ($) Air-craft	Jan. 28, 2019 USD ($)	Aug. 14, 2018 USD ($)	Jun. 28, 2018 USD ($) Air-craft shares	Jun. 27, 2018 USD ($) Air-craft	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) shares	Jun. 30, 2018 USD ($)	Jun. 30, 2019 USD ($) shares	Jun. 30, 2018 USD ($)	Sep. 30, 2018 USD ($)
Debt Instrument [Line Items]
Property and equipment, net							$ 1,286,022		$ 1,286,022		$ 1,250,829
Long-Term Debt							896,730		896,730		$ 930,207
Non-cash lease termination expense							$ 9,540	$ 15,109	$ 9,540	$ 15,109
Warrants to purchase shares of common stock \| shares							250,000		250,000
CIT revolving credit facility outstanding			$ 25,700
Loss on extinguishment of debt									$ 3,616
Payment for debt extinguishment prepayment penalties									1,672
CRJ-900 [Member]
Debt Instrument [Line Items]
Refinanced debt					$ 16,000
Number of aircraft under refinanced debt \| Air-craft				6	6
Debt instrument, face amount				$ 69,600	$ 27,500
Net cash proceeds after transaction related fees					$ 10,400
Long term debt interest rate description				LIBOR plus a spread ranging from 3.50% for the senior promissory notes to 7.50% for the subordinated promissory notes	LIBOR plus 3.50%.
Long term debt, basis spread on variable rate					3.50%
Number of aircraft purchased \| Air-craft				9
Payment for aircraft purchased				$ 76,500
Number of aircraft financed \| Air-craft				6	6
Non-cash lease termination expense				$ 15,100
Future goods and services credits				4,500
Loan forgiveness for loans				$ 5,600
Warrants to purchase shares of common stock \| shares				250,000
CRJ-700 Aircraft [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	$ 70,000
Long term debt interest rate description	LIBOR plus 5.25%.
Long term debt, basis spread on variable rate	5.25%
Number of aircraft purchased \| Air-craft	10
Payment for aircraft purchased	$ 70,000
Non-cash lease termination expense	$ 9,500
Equipment Notes [Member]
Debt Instrument [Line Items]
Long-Term Debt							$ 200,300		$ 200,300
Senior Notes Due 2020 [Member] \| CRJ-900 [Member]
Debt Instrument [Line Items]
Debt instrument, face amount						$ 65,800		65,800		65,800
Long term debt, basis spread on variable rate				3.50%		3.50%
Senior Notes Due 2020 [Member] \| CRJ-900 [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Long term debt interest rate description									three-month LIBOR plus 3.50%
Subordinated Notes Due 2020 [Member] \| CRJ-900 [Member]
Debt Instrument [Line Items]
Debt instrument, face amount						$ 29,800		$ 29,800		$ 29,800
Long term debt, basis spread on variable rate				7.50%		7.50%
Subordinated Notes Due 2020 [Member] \| CRJ-900 [Member] \| LIBOR [Member]
Debt Instrument [Line Items]
Long term debt interest rate description									three month LIBOR plus 7.50%
Term Loan
Debt Instrument [Line Items]
Debt instrument, face amount		$ 91,200
Long term debt interest rate description		LIBOR plus 3.10%
Term loan, term		5 years
Write-off of financing cost		$ 1,900
Payment for debt extinguishment prepayment penalties		$ 1,700
Term Loan \| Spare Engine Facility [Member]
Debt Instrument [Line Items]
Long term debt interest rate description		LIBOR plus 7.25%
Loss on extinguishment of debt		$ 3,600
Term Loan \| LIBOR [Member]
Debt Instrument [Line Items]
Long term debt, basis spread on variable rate		3.10%
Term Loan \| LIBOR [Member] \| Spare Engine Facility [Member]
Debt Instrument [Line Items]
Long term debt, basis spread on variable rate		7.25%
Aircraft and Equipment [Member] \| Pledged as Collateral [Member]
Debt Instrument [Line Items]
Property and equipment, net							$ 1,203,000		$ 1,203,000