XML 44 R33.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Organization and Operations - Additional Information (Detail) $ / shares in Units, $ in Millions |  |  |  | 3 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | ---
Sep. 11, 2018 $ / shares shares | Aug. 14, 2018 USD ($) $ / shares shares | Aug. 08, 2018 shares | Dec. 31, 2018 USD ($) Daily_Departure State Air-craft City Employee Extension shares | Sep. 30, 2017 Air-craft Extension | Sep. 30, 2018 shares
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Number of states in which entity operates | State |  |  |  | 40 |  |
Number of aircrafts operated | Air-craft |  |  |  | 145 |  |
Number of cities in which entity operates | City |  |  |  | 121 |  |
Number of daily departures | Daily_Departure |  |  |  | 628 |  |
Number of employees | Employee |  |  |  | 3,400 |  |
Common stock, stock split |  |  |  | Effected a 2.5-for-1 stock split |  |
Stock split ratio |  |  | 2.5 |  |  |
Common stock, shares authorized |  |  | 125,000,000 | 125,000,000 |  | 125,000,000
Preferred stock, shares authorized |  |  | 5,000,000 | 5,000,000 |  | 5,000,000
Stock issued during period, shares, new issues | 1,344,500 |  |  |  |  |
Common stock, warrants issued |  |  |  | 10,614,990 |  | 10,614,990
Notice period for termination of agreement |  |  |  | The capacity purchase agreement is also subject to early termination for cause under specified circumstances and subject to the Company's right to cure under certain circumstances. United is also permitted, subject to certain conditions, to terminate the agreement early in its discretion by giving us notice of 90 days or more |  |
Payment of lease cost | $ |  |  |  | $ 1.9 |  |
United [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Number of extension | Extension |  |  |  | 4 | 4 |
Renewal term extension period |  |  |  | 2 years | 2 years |
Maximum [Member] | United [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Aggregate extension period |  |  |  | 8 years | 8 years |
CRJ-900 Aircraft [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Number of aircrafts operated | Air-craft |  |  |  | 64 |  |
CRJ-700 Aircraft [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Number of aircrafts operated | Air-craft |  |  |  | 20 |  |
CRJ-700 Aircraft [Member] | Minimum [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Early termination right, expiration period |  |  |  | 2019-08 |  |
CRJ-700 Aircraft [Member] | Maximum [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Early termination right, expiration period |  |  |  | 2019-12 |  |
E-175 Aircraft [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Number of aircrafts operated | Air-craft |  |  |  | 60 |  |
E-175 Aircraft [Member] | Mesa [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Number of aircrafts operated | Air-craft |  |  |  | 18 |  |
E-175 Aircraft [Member] | United [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Number of aircrafts operated | Air-craft |  |  |  | 30 | 12 |
E-175 Aircraft [Member] | Minimum [Member] | Mesa [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Early termination right, expiration period |  |  |  | 2028-01 |  |
E-175 Aircraft [Member] | Minimum [Member] | United [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Early termination right, expiration period |  |  |  | 2019-06 |  |
E-175 Aircraft [Member] | Maximum [Member] | Mesa [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Early termination right, expiration period |  |  |  | 2028-11 |  |
E-175 Aircraft [Member] | Maximum [Member] | United [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Early termination right, expiration period |  |  |  | 2020-08 |  |
American Airlines Inc. [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Ownership interest |  |  |  | 7.20% |  | 7.20%
Restricted Stock [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Number of Shares, Granted |  |  |  | 0 |  |
2018 Equity Incentive Plan [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] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Number of Shares, Granted |  | 1,266,034 |  |  |  |
Number of Shares, vested |  | 966,022 |  |  |  |
2018 Equity Incentive Plan [Member] | Restricted Stock [Member] | Employees [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Additional restricted common stock shares issued |  | 983,113 |  |  |  |
2011 and 2017 Plans [Member] | Restricted Stock [Member] | Employees [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Cancellation of common stock shares existing unvested restricted phantom units |  | 491,915 |  |  |  |
Cancellation of common stock shares existing of unvested restricted stock |  | 491,198 |  |  |  |
IPO [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 |  | $ 124.2 |  |
Net proceeds from initial public offering | $ |  |  |  | 111.7 |  |
Underwriting discounts and commissions | $ |  |  |  | 8.7 |  |
Offering costs | $ |  |  |  | $ 3.8 |  |
Underwriter Options [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Common stock, warrants issued |  | 1,444,500 |  |  |  |
Purchased Directly From Company [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Stock issued during period, shares, new issues | 723,985 |  |  |  |  |
Purchased Directly From Selling Shareholders [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Stock issued during period, shares, new issues | 620,515 |  |  |  |  |
Firm Shares and Option Shares [Member] |  |  |  |  |  |
Organization Consolidation And Presentation Of Financial Statements [Line Items] |  |  |  |  |  |
Shares issued, price per share | $ / shares | $ 12.00 |  |  |  |  |

X
- Definition Aggregate extension period. + References No definition available. + Details
Name: | mesa_AggregateExtensionPeriod
Namespace Prefix: | mesa_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Airline services in number of cities. + References No definition available. + Details
Name: | mesa_AirlineServicesInNumberOfCities
Namespace Prefix: | mesa_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Class of warrants or right issued. + References No definition available. + Details
Name: | mesa_ClassOfWarrantsOrRightIssued
Namespace Prefix: | mesa_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Early termination right, expiration month year. + References No definition available. + Details
Name: | mesa_EarlyTerminationRightExpirationMonthYear
Namespace Prefix: | mesa_
Data Type: | xbrli:gYearMonthItemType
Balance Type: | na
Period Type: | duration

X
- Definition Issuance of stock upon cancellation of existing unvested restricted phantom stock units. + References No definition available. + Details
Name: | mesa_IssuanceOfStockUponCancellationOfExistingUnvestedRestrictedPhantomStockUnits
Namespace Prefix: | mesa_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Issuance of stock upon cancellation of existing unvested restricted phantom stock units and restricted stock units. + References No definition available. + Details
Name: | mesa_IssuanceOfStockUponCancellationOfExistingUnvestedRestrictedPhantomStockUnitsAndRestrictedStockUnits
Namespace Prefix: | mesa_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Issuance of stock upon cancellation of existing unvested restricted stock. + References No definition available. + Details
Name: | mesa_IssuanceOfStockUponCancellationOfExistingUnvestedRestrictedStock
Namespace Prefix: | mesa_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Notice period for termination of agreement. + References No definition available. + Details
Name: | mesa_NoticePeriodForTerminationOfAgreement
Namespace Prefix: | mesa_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of daily departures. + References No definition available. + Details
Name: | mesa_NumberOfDailyDepartures
Namespace Prefix: | mesa_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of employees. + References No definition available. + Details
Name: | mesa_NumberOfEmployees
Namespace Prefix: | mesa_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of extension for renewal. + References No definition available. + Details
Name: | mesa_NumberOfExtensionForRenewal
Namespace Prefix: | mesa_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Offering costs. + References No definition available. + Details
Name: | mesa_OfferingCosts
Namespace Prefix: | mesa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Organization consolidation and presentation of financial statements. + References No definition available. + Details
Name: | mesa_OrganizationConsolidationAndPresentationOfFinancialStatementsLineItems
Namespace Prefix: | mesa_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Proceeds from issuance initial public offering net of issuance costs. + References No definition available. + Details
Name: | mesa_ProceedsFromIssuanceInitialPublicOfferingNetOfIssuanceCosts
Namespace Prefix: | mesa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Renewal term extension period. + References No definition available. + Details
Name: | mesa_RenewalTermExtensionPeriod
Namespace Prefix: | mesa_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Stock Withheld To Cover Tax Withholding Requirements Upon Vesting To Restricted Stock Units Shares + References No definition available. + Details
Name: | mesa_StockWithheldToCoverTaxWithholdingRequirementsUponVestingToRestrictedStockUnitsShares
Namespace Prefix: | mesa_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Underwriting discounts and commissions. + References No definition available. + Details
Name: | mesa_UnderwritingDiscountsAndCommissions
Namespace Prefix: | mesa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The maximum number of common shares permitted to be issued by an entity's charter and bylaws. + 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(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CommonStockSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The parent entity's interest in net assets of the subsidiary, expressed as a percentage. + References No definition available. + Details
Name: | us-gaap_MinorityInterestOwnershipPercentageByParent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of aircraft operated by the carrier. + References No definition available. + Details
Name: | us-gaap_NumberOfAircraftOperated
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of states the entity operates in as of the balance sheet date. + References No definition available. + Details
Name: | us-gaap_NumberOfStatesInWhichEntityOperates
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of cash outflow for costs that are essential to originate the lease and would not otherwise have been incurred without the lease agreement. Amount includes, but is not limited to, cash outflows to evaluate the lessee's credit condition, guarantees, and collateral and cash outflows for costs incurred in negotiating, processing, and executing the lease agreement. + References No definition available. + Details
Name: | us-gaap_PaymentsForLeasingCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws. + 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(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_PreferredStockSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition The cash inflow associated with the amount received from entity's first offering of stock to the public. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceInitialPublicOffering
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The number of restricted shares issued as compensation, net of shares for the payment of withholding taxes. This element is to be used only if shares are used in lieu of cash to satisfy all or a portion of withholding taxes. + References No definition available. + Details
Name: | us-gaap_RestrictedStockSharesIssuedNetOfSharesForTaxWithholdings
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=109197908&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of options vested. + References No definition available. + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedNumberOfShares
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Per share or per unit amount of equity securities issued. + References No definition available. + Details
Name: | us-gaap_SharesIssuedPricePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of new stock issued during the period. + 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(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 4: 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(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Description of the stock split arrangement. Also provide the retroactive effect given by a stock split that occurs after the balance date but before the release of financial statements. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SAB Topic 4.C) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770 + Details
Name: | us-gaap_StockholdersEquityNoteStockSplit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SAB TOPIC 4.C) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770 + Details
Name: | us-gaap_StockholdersEquityNoteStockSplitConversionRatio1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | srt_MajorCustomersAxis=mesa_UnitedAirlinesIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=mesa_CRJ900AircraftMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=mesa_CRJ700AircraftMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=mesa_E175AircraftMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ConsolidatedEntitiesAxis=srt_ParentCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_OwnershipAxis=mesa_AmericanAirlinesIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=mesa_TwoThousandAndEighteenEquityIncentivePlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TitleOfIndividualAxis=mesa_EmployeesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=mesa_TwoThousandElevenAndTwoThousandSeventeenEquityIncentivePlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=us-gaap_IPOMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=mesa_UnderwriterOptionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=mesa_PurchasedDirectlyFromEntityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=mesa_PurchasedDirectlyFromSellingShareholdersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsidiarySaleOfStockAxis=mesa_FirmSharesAndOptionSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |