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Organization and Operations - Additional Information (Detail) $ / shares in Units, $ in Millions |  | 9 Months Ended |
--- | --- | --- | ---
Aug. 14, 2018 USD ($) $ / shares shares | Jun. 30, 2018 USD ($) Daily_Departure Aircraft States City shares | Sep. 30, 2017 shares
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |
Number of states in which entity operates | States |  | 38 |
Number of aircrafts operated | Aircraft |  | 145 |
Number of cities in which entity operates | City |  | 115 |
Number of daily departures | Daily_Departure |  | 600 |
Common stock, warrants issued |  | 10,871,730 | 12,230,625
Payment of lease cost | $ |  | $ 1.9 |
IPO [Member] | Subsequent Event [Member] |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |
Stock issued during period, shares, new issues | 9,630,000 |  |
Shares issued, price per share | $ / shares | $ 12.00 |  |
Gross proceeds of initial public offering | $ | $ 115.6 |  |
Underwriter Options Member | Subsequent Event [Member] |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |
Common stock, warrants issued | 777,833 |  |
Restricted Stock [Member] |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |
Number of Shares, Granted |  | 0 |
CRJ-900 Aircraft [Member] |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |
Number of aircrafts operated | Aircraft |  | 64 |
CRJ-700 Aircraft [Member] |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |
Number of aircrafts operated | Aircraft |  | 20 |
E-175 Aircraft [Member] |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |
Number of aircrafts operated | Aircraft |  | 60 |
2018 Equity Incentive Plan [Member] | Subsequent Event [Member] |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |
Stock withheld to cover tax withholding requirements upon vesting to restricted stock units shares | 314,198 |  |
Restricted stock, shares issued net of shares for tax withholdings | 651,824 |  |
2018 Equity Incentive Plan [Member] | Restricted Stock [Member] | Subsequent Event [Member] |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |
Number of Shares, Granted | 1,266,034 |  |
Number of Shares, vested | 966,022 |  |
American Airlines Inc. [Member] |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |
Ownership interest |  | 10.70% |

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