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Long-Term Debt, Financing Leases and Other Borrowings - Schedule of Long-term Debt (Parenthetical) (Detail) |  |  |  |  | 1 Months Ended | 3 Months Ended | 6 Months Ended | 12 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Nov. 12, 2020 USD ($) Air-craft | Oct. 30, 2020 USD ($) | Sep. 27, 2019 USD ($) | Sep. 25, 2019 USD ($) | Jun. 30, 2019 USD ($) Airfleet | Jan. 31, 2019 USD ($) | Jun. 30, 2018 USD ($) Air-craft | Feb. 28, 2018 Engine | Dec. 31, 2017 USD ($) Air-craft | Jun. 30, 2020 USD ($) | Dec. 31, 2019 | Mar. 31, 2021 USD ($) | Mar. 31, 2020 USD ($) | Sep. 30, 2020 | Sep. 30, 2019 USD ($) | Sep. 30, 2018 USD ($) | Sep. 30, 2017 USD ($) | Sep. 30, 2016 USD ($) Air-craft | Sep. 30, 2015 USD ($) Air-craft | Nov. 14, 2020 USD ($) | Nov. 13, 2020 USD ($) | Sep. 30, 2014 USD ($) Airfleet | Sep. 30, 2007 USD ($) Airfleet
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from long-term debt |  |  |  |  |  |  |  |  |  |  |  | $ 195,000,000 | $ 23,000,000 |  |  |  |  |  |  |  |  |  |
Loan Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of aircraft financed | Air-craft | 44 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Repayments of long term debt | $ 167,700,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Secured term loan facility, amount borrowed |  | $ 43,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Secured term loan facility, additional amount borrowed |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 152,000,000 |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Aircraft, Due 2022 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity year |  |  |  |  |  |  |  |  |  |  |  | 2022 |  | 2022 |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Aircraft, Due 2022 [Member] | CRJ-900 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of aircraft refinanced | Airfleet |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3
Notes Payable to Financial Institution, Collateralized by the Underlying Aircraft, Due 2022 [Member] | CRJ-700 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of aircraft refinanced | Airfleet |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3
Notes Payable to Financial Institution, Collateralized by the Underlying Aircraft, Due 2022 [Member] | Three C- R- J-900 and Three C- R- J-700 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 120,300,000
Long term debt interest rate description |  |  |  |  |  |  |  |  |  |  |  | monthly LIBOR plus 2.25% |  |  |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Aircraft, Due 2022 [Member] | Three C- R- J-900 and Three C- R- J-700 [Member] | LIBOR [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt, basis spread on variable rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2.25% |  |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Aircraft, Due 2022 [Member] | Ten C- R- J-900 Aircraft [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 88,400,000 |
Long term debt interest rate description |  |  |  |  |  |  |  |  |  |  |  | monthly LIBOR plus 1.95% |  |  |  |  |  |  |  |  |  |  |
Number of aircraft financed | Airfleet |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10 |
Long term debt interest rate percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1.95% |
Repayments of long term debt |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 40,000,000.0 |  |  |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Aircraft, Due 2024 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity year |  |  |  |  |  |  |  |  |  |  |  | 2024 |  | 2024 |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Aircraft, Due 2024 [Member] | Eight C- R- J-900 Aircraft [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 114,500,000 |
Number of aircraft financed | Airfleet |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 8 |
Long term debt interest rate percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5.00% |
Senior and Subordinated Notes Payable to Secured Parties, Collateralized by the Underlying Aircraft, Due 2027 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity year |  |  |  |  |  |  |  |  |  |  |  | 2027 |  | 2027 |  |  |  |  |  |  |  |  |
Senior and Subordinated Notes Payable to Secured Parties, Collateralized by the Underlying Aircraft, Due 2027 [Member] | CRJ-900 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 170,200,000 |  |  |  |
Number of aircraft financed | Air-craft |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 7 |  |  |  |
Notes Payable to Secured Parties, Collateralized by the Underlying Aircraft, Due 2028 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity year |  |  |  |  |  |  |  |  |  |  |  | 2028 |  | 2028 |  |  |  |  |  |  |  |  |
Notes Payable to Secured Parties, Collateralized by the Underlying Aircraft, Due 2028 [Member] | Ten E-175 Aircraft [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 246,000,000.0 |  |  |  |  |
Number of aircraft financed | Air-craft |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10 |  |  |  |  |
Notes Payable to Secured Parties, Collateralized by the Underlying Aircraft, Due 2028 [Member] | Ten E-175 Aircraft [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt interest rate percentage |  |  |  |  |  |  |  |  |  |  |  | 4.75% |  |  |  |  |  |  |  |  |  |  |
Notes Payable to Secured Parties, Collateralized by the Underlying Aircraft, Due 2028 [Member] | Ten E-175 Aircraft [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt interest rate percentage |  |  |  |  |  |  |  |  |  |  |  | 6.25% |  |  |  |  |  |  |  |  |  |  |
Senior and Subordinated Notes Payable to Secured Parties, Collateralized by the Underlying Aircraft, Due 2028 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity year |  |  |  |  |  |  |  |  |  |  |  | 2028 |  | 2028 |  |  |  |  |  |  |  |  |
Senior and Subordinated Notes Payable to Secured Parties, Collateralized by the Underlying Aircraft, Due 2028 [Member] | Eight E-175 Aircraft [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of aircraft refinanced | Air-craft |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 8 |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 195,300,000 |  |  |  |  |
Senior and Subordinated Notes Payable to Secured Parties, Collateralized by the Underlying Aircraft, Due 2022 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity year |  |  |  |  |  |  |  |  |  |  |  | 2022 |  | 2022 |  |  |  |  |  |  |  |  |
Senior and Subordinated Notes Payable to Secured Parties, Collateralized by the Underlying Aircraft, Due 2022 [Member] | CRJ-900 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity year |  |  |  |  |  |  |  |  |  |  |  | 2022 |  | 2022 |  |  |  |  |  |  |  |  |
Number of aircraft refinanced | Air-craft |  |  |  |  |  |  | 6 |  | 9 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  | $ 27,500,000 |  | $ 74,900,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of aircraft financed | Air-craft |  |  |  |  |  |  | 9 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Senior and Subordinated Notes Payable to Secured Parties, Collateralized by the Underlying Aircraft, Due 2022 [Member] | CRJ-900 [Member] | Capital Lease Obligations [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  | $ 69,600,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Equipment, Due 2020 [Member] | Flight Equipment Maintenance [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity year |  |  |  |  |  |  |  |  |  |  |  | 2020 |  | 2020 |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Equipment, Due 2020 [Member] | Flight Equipment Maintenance [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 26,100,000 | $ 26,100,000 | $ 26,100,000 | $ 26,100,000 |  |  |  |  |
Long term debt interest rate description |  |  |  |  |  |  |  |  |  |  |  | three-month LIBOR plus a spread ranging from 2.93% to 3.21% |  |  |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Equipment, Due 2020 [Member] | Flight Equipment Maintenance [Member] | LIBOR [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt, basis spread on variable rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2.93% | 2.93% | 2.93% | 2.93% |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Equipment, Due 2020 [Member] | Flight Equipment Maintenance [Member] | LIBOR [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt, basis spread on variable rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3.21% | 3.21% | 3.21% | 3.21% |  |  |  |  |
Notes Payable to Financial Institution Due 2020 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity year |  |  |  |  |  |  |  |  |  |  |  | 2020 |  | 2020 |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution Due 2020 [Member] | Flight Equipment Maintenance [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 10,200,000 | $ 10,200,000 |  |  |  |
Long term debt interest rate description |  |  |  |  |  |  |  |  |  |  |  | three-month LIBOR plus 3.07% |  |  |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution Due 2020 [Member] | Flight Equipment Maintenance [Member] | LIBOR [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt interest rate percentage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 3.07% | 3.07% |  |  |  |
Other Obligations Due to Financial Institution, Collateralized by the Underlying Equipment, Due 2023 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity year |  |  |  |  |  |  |  |  |  |  |  | 2023 |  | 2023 |  |  |  |  |  |  |  |  |
Imputed interest |  |  |  |  |  |  |  | 9.128% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of spare engines leased | Engine |  |  |  |  |  |  |  | 2 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Equipment, Due 2024 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity year |  |  |  |  |  |  |  |  |  |  |  | 2024 |  | 2024 |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Equipment, Due 2024 [Member] | Flight Equipment Maintenance [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  | $ 91,200,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt interest rate description |  |  |  |  |  |  |  |  |  |  |  | monthly LIBOR plus 3.10% |  |  |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Equipment, Due 2024 [Member] | Flight Equipment Maintenance [Member] | LIBOR [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt, basis spread on variable rate |  |  |  |  |  | 3.10% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Aircraft, Due 2023 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity year |  |  |  |  |  |  |  |  |  |  |  | 2023 |  | 2023 |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Aircraft, Due 2023 [Member] | CRJ-700 Aircraft [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  | $ 70,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt interest rate description |  |  |  |  |  |  |  |  |  |  |  | monthly LIBOR plus 5.00% |  |  |  |  |  |  |  |  |  |  |
Number of aircraft financed | Airfleet |  |  |  |  | 10 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Aircraft, Due 2023 [Member] | CRJ-700 Aircraft [Member] | LIBOR [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt, basis spread on variable rate |  |  |  |  | 5.25% |  |  |  |  |  | 5.00% |  |  |  | 5.25% |  |  |  |  |  |  |  |
Notes Payable to Financial Institution Due 2023 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity year |  |  |  |  |  |  |  |  |  |  |  | 2023 |  | 2023 |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution Due 2023 [Member] | Flight Equipment Maintenance [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  | $ 8,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt interest rate description |  |  |  |  |  |  |  |  |  |  |  | monthly LIBOR plus 5.00% |  |  |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution Due 2023 [Member] | Flight Equipment Maintenance [Member] | LIBOR [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt, basis spread on variable rate |  |  | 5.25% |  |  |  |  |  |  |  | 5.00% |  |  |  | 5.25% |  |  |  |  |  |  |  |
Notes Payable to Financial Institution Due 2025 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity year |  |  |  |  |  |  |  |  |  |  |  | 2025 |  | 2025 |  |  |  |  |  |  |  |  |
Senior Notes Due Two Thousand Twenty Seven [Member] | CRJ-900 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 151,000,000.0 |  |  |  |
Long term debt interest rate description |  |  |  |  |  |  |  |  |  |  |  | monthly LIBOR plus 2.71% |  |  |  |  |  |  |  |  |  |  |
Senior Notes Due Two Thousand Twenty Seven [Member] | CRJ-900 [Member] | LIBOR [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt, basis spread on variable rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2.71% |  |  |  |
Subordinated Notes Due Two Thousand Twenty Seven [Member] | CRJ-900 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Imputed interest |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6.25% |  |  |  |
Debt discount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 8,100,000 |  |  |  |
Senior Notes Due 2008 [Member] | Eight E-175 Aircraft [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt interest rate description |  |  |  |  |  |  |  |  |  |  |  | three-month LIBOR plus a spread ranging from 2.20% to 2.32% |  |  |  |  |  |  |  |  |  |  |
Senior Notes Due 2008 [Member] | Eight E-175 Aircraft [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 172,000,000.0 |  |  |  |  |
Senior Notes Due 2008 [Member] | Eight E-175 Aircraft [Member] | LIBOR [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt, basis spread on variable rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2.20% |  |  |  |  |
Senior Notes Due 2008 [Member] | Eight E-175 Aircraft [Member] | LIBOR [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt, basis spread on variable rate |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2.32% |  |  |  |  |
Subordinated Notes Due 2008 [Member] | Eight E-175 Aircraft [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt interest rate percentage |  |  |  |  |  |  |  |  |  |  |  | 4.50% |  |  |  |  |  |  |  |  |  |  |
Senior Notes Due 2020 [Member] | CRJ-900 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  | $ 65,800,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt, basis spread on variable rate |  |  |  |  |  |  | 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 |  |  |  |  |  |  | $ 29,800,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt, basis spread on variable rate |  |  |  |  |  |  | 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% |  |  |  |  |  |  |  |  |  |  |
Senior Notes due Two Thousand Twenty Two [Member] | CRJ-900 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  | $ 46,900,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt interest rate description |  |  |  |  |  |  |  |  |  |  |  | three-month LIBOR plus 3.50% |  |  |  |  |  |  |  |  |  |  |
Senior Notes due Two Thousand Twenty Two [Member] | CRJ-900 [Member] | LIBOR [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt, basis spread on variable rate |  |  |  |  |  |  |  |  | 3.50% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subordinated Notes DueTwoThousandTwentyTwo [Member] | CRJ-900 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt interest rate description |  |  |  |  |  |  |  |  |  |  |  | three-month LIBOR plus 4.50% |  |  |  |  |  |  |  |  |  |  |
Subordinated Notes DueTwoThousandTwentyTwo [Member] | CRJ-900 [Member] | LIBOR [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt interest rate percentage |  |  |  |  |  |  |  |  | 4.50% |  |  |  |  |  |  |  |  |  |  |  |  |  |
Working Capital Draw Loan [Member] | Revolving Credit Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  | $ 35,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt interest rate description |  |  |  |  |  |  |  |  |  |  |  | one-month LIBOR plus 3.75% |  |  |  |  |  |  |  |  |  |  |
Term loan, term |  |  |  | 3 years |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, expiration year and month |  |  |  | 2022-09 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Proceeds from long-term debt |  |  |  |  |  |  |  |  |  | $ 23,000,000.0 |  | $ 22,900,000 |  |  |  |  |  |  |  |  |  |  |
Working Capital Draw Loan [Member] | LIBOR [Member] | Revolving Credit Facility [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, basis spread on variable rate |  | 3.50% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt interest rate description |  |  |  |  |  |  |  |  |  |  |  | three-month LIBOR plus 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 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 0 | $ 152,000,000.0 |  |
Debt instrument, maturity date |  | Oct. 30, 2025 |  |  |  |  |  |  |  |  |  | Oct. 30, 2025 |  |  |  |  |  |  |  |  |  |  |

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- Definition Debt instrument, expiration month and year. + References No definition available. + Details
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- Definition Debt instrument imputed interest rate. + References No definition available. + Details
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- Definition Number of aircraft financed. + References No definition available. + Details
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- Definition Number of spare engines leased. + References No definition available. + Details
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- Definition 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. + References No definition available. + Details
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- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
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- Definition Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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