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Organization and Operations - Additional Information (Detail) $ / shares in Units, $ in Thousands |  |  |  |  |  |  |  |  |  | 1 Months Ended | 3 Months Ended | 9 Months Ended | 12 Months Ended |  |
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Nov. 28, 2025 | Oct. 24, 2025 USD ($) | Oct. 01, 2025 USD ($) | Apr. 04, 2025 USD ($) NonEmployeeDirectors $ / shares shares | Apr. 01, 2025 USD ($) AirCraft | Mar. 18, 2025 | Dec. 31, 2024 USD ($) AirCraft $ / shares shares | Dec. 23, 2024 | Jan. 13, 2023 shares | Jan. 31, 2024 AirCraft | Sep. 30, 2025 USD ($) DailyDeparture State $ / shares shares | Jun. 30, 2025 USD ($) | Mar. 31, 2025 USD ($) | Sep. 30, 2024 USD ($) | Jun. 30, 2024 USD ($) | Mar. 31, 2024 USD ($) | Sep. 30, 2025 USD ($) DailyDeparture AirCraft State City $ / shares shares | Sep. 30, 2024 USD ($) | Sep. 30, 2025 USD ($) DailyDeparture State $ / shares shares | Nov. 20, 2025 Engine | Dec. 27, 2022 USD ($)
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of states in which entity operates | State |  |  |  |  |  |  |  |  |  |  | 32 |  |  |  |  |  | 32 |  | 32 |  |
Number of cities in which entity operates | City |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 76 |  |  |  |
Number of daily departures | DailyDeparture |  |  |  |  |  |  |  |  |  |  | 234 |  |  |  |  |  | 234 |  | 234 |  |
Common stock, no par value | $ / shares |  |  |  |  |  |  | $ 0 |  |  |  | $ 0 |  |  |  |  |  | $ 0 |  | $ 0 |  |
Net loss |  |  |  |  |  |  |  |  |  |  | $ (14,124) | $ 20,855 | $ (58,631) | $ (24,917) | $ (19,908) | $ 11,660 | $ (51,898) | $ (33,165) |  |  |
Current portion of long-term debt |  |  |  |  |  |  | $ 143,275 |  |  |  | 68,009 |  |  |  |  |  | 68,009 |  | $ 68,009 |  |
Long-term debt |  |  |  |  |  |  |  |  |  |  | 68,000 |  |  |  |  |  | 68,000 |  | 68,000 |  |
Debt outstanding |  |  |  |  |  |  | $ 230,608 |  |  |  | 95,215 |  |  |  |  |  | 95,215 |  | $ 95,215 |  |
Impairment loss |  |  |  |  |  |  |  |  |  |  | $ 7,300 |  |  |  |  |  | $ 53,400 |  |  |  |
Consideration For Amended Description |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Additionally, in January 2023, in consideration for entering in the Amended and Restated United CPA and providing the revolving line of credit, discussed in Note 8, the Company (i) granted United the right to designate one individual to the Company's board of directors (the "United Designee"), which occurred effective May 2, 2023 with the appointment of Jonathan Ireland and (ii) issued to United 4,042,061 shares of the Company’s common stock equal to approximately 10% of the Company’s issued and outstanding capital stock on such date (the "United Shares"). United's board designee rights will terminate at such time as United's equity ownership in the Company falls below five percent (5%) of the Company's issued and outstanding stock |  |  |  |
United capacity purchase agreement termination notice period |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 30 days |  |
Common stock, shares issued | shares |  |  |  |  |  |  | 41,331,719 |  |  |  | 41,879,859 |  |  |  |  |  | 41,879,859 |  | 41,879,859 |  |
Purcahse of aircraft |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 5,023 | $ 13,429 |  |  |
Merger Agreement with Republic Airways Holdings, Inc. [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock , par value | $ / shares |  |  |  | $ 0.001 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Right to receive shares of common stock | shares |  |  |  | 584.9 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock, no par value | $ / shares |  |  |  | $ 0 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Termination fee |  |  |  | $ 1,500 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of shares issues at closing of merger |  |  |  | 6.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of Non employee Directors | NonEmployeeDirectors |  |  |  | 7 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percenatge of interest upon effectiveness of the Merger |  |  |  | 12.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Merger Agreement with Republic Airways Holdings, Inc. [Member] | Republic [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of Non employee Directors | NonEmployeeDirectors |  |  |  | 6 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Merger Agreement with Republic Airways Holdings, Inc. [Member] | Mesa [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of Non employee Directors | NonEmployeeDirectors |  |  |  | 1 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stockholders of Republic [Member] | Merger Agreement with Republic Airways Holdings, Inc. [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percenatge of interest upon effectiveness of the Merger |  |  |  | 88.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Stockholders of Mesa [Member] | Merger Agreement with Republic Airways Holdings, Inc. [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percenatge of interest upon effectiveness of the Merger |  |  |  | 6.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ownership Limitation Post-Merger [Member] | Merger Agreement with Republic Airways Holdings, Inc. [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percenatge of interest upon effectiveness of the Merger |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 30.00% |
Maximum [Member] | Additional Equity Interests [Member] | Merger Agreement with Republic Airways Holdings, Inc. [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percenatge of interest upon effectiveness of the Merger |  |  |  | 6.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Impairment loss |  |  | $ 7,100 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gross proceeds from sale of asset |  |  | 15,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
United Revolving Credit Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revolving loan |  |  |  |  |  |  |  |  |  |  | $ 10,700 |  |  |  |  |  | $ 10,700 |  | $ 10,700 |  |
United Capacity Purchase Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reimbursement of transition expenses |  |  |  |  | $ 14,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
United Capacity Purchase Agreement [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of aircrafts operated | AirCraft |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 60 |  |  |  |
United Capacity Purchase Agreement [Member] | Revolving Credit Facility [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Revolving loan |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 10,500
United Capacity Purchase Agreement [Member] | United [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Common stock issued equivalent percentage of issued and outstanding capital stock |  |  |  |  |  |  |  |  | 10.00% |  |  |  |  |  |  |  |  |  |  |  |
Common stock, shares issued | shares |  |  |  |  |  |  |  |  | 4,042,061 |  |  |  |  |  |  |  |  |  |  |  |
E-175 Aircraft [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of aircrafts operated | AirCraft |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 60 |  |  |  |
Number of aircraft sold | AirCraft |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 18 |  |  |  |
E-175 Aircraft [Member] | United [Member] | December 31, 2024 and January 31, 2025 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of aircraft sold | AirCraft |  |  |  |  |  |  | 18 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds from sale of asset |  |  |  |  |  |  | $ 227,700 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Discounted amount |  |  |  |  |  |  | $ 20,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of aircrafts owned | AirCraft |  |  |  |  |  |  | 60 |  |  |  |  |  |  |  |  |  |  |  |  |  |
E-175 Aircraft [Member] | United Capacity Purchase Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of aircrafts operated | AirCraft |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 60 |  |  |  |
E-175 Aircraft [Member] | United Capacity Purchase Agreement [Member] | United [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notice period for termination of agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | United, subject to certain conditions, including the payment of certain costs tied to aircraft type, to terminate the agreement in its discretion, or remove aircraft from service, by giving us notice of 90 days or more |  |  |  |
E-175 Aircraft [Member] | United Capacity Purchase Agreement [Member] | United [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Lease expiration year |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2026 |  |  |  |
E-175 Aircraft [Member] | United Capacity Purchase Agreement [Member] | United [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Lease expiration year |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2028 |  |  |  |
E175LL Aircraft [Member] | United Capacity Purchase Agreement [Member] | United [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Notice period for termination of agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | United, subject to certain conditions, including the payment of certain costs tied to aircraft type, may terminate the agreement in its discretion, or remove E-175 aircraft from service, by giving us notice of 90 days or more |  |  |  |
CRJ-900 and E-175 Aircraft [Member] | United Capacity Purchase Agreement [Member] | United [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of combined fleet | AirCraft |  |  |  |  | 60 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
CRJ-900 Covered Aircraft [Member] | United Capacity Purchase Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of aircrafts to be removed | AirCraft |  |  |  |  |  |  |  |  |  | 8 |  |  |  |  |  |  |  |  |  |  |
CRJ-Related Assets [Member] | Merger Agreement with Republic Airways Holdings, Inc. [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Assets Not Sold | Engine |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 11 |
UST Loan [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt outstanding |  |  |  |  |  |  |  |  |  |  | $ 62,200 |  |  |  |  |  | $ 62,200 |  | $ 62,200 |  |
Debt instrument, maturity date |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | Oct. 30, 2025 |  |  |  |
UST Loan [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Minimum collateral coverage ratio |  |  |  |  |  | 91 |  | 99 |  |  |  |  |  |  |  |  |  |  |  |  |
UST Loan [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Gross proceeds from sale of asset |  |  | $ 12,100 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Pay off Outstanding Debt [Member] | E-175 Aircraft [Member] | United [Member] | December 31, 2024 and January 31, 2025 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds from sale of asset |  |  |  |  |  |  | $ 69,600 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Withheld by United for Assumption of Debt [Member] | E-175 Aircraft [Member] | United [Member] | December 31, 2024 and January 31, 2025 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Net proceeds from sale of asset |  |  |  |  |  |  | $ 73,400 |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amendment to Loan and Guarantee Agreement [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, maturity date | Nov. 28, 2025 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Interest rate under the Loan Agreement |  | (0.00%) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Principal amount of the Obligation |  | $ 12,300 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount deposited in collateral account |  | 31,900 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Non-refundable advisory fee |  | $ 3,500 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |

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