XML 55 R44.htm IDEA: XBRL DOCUMENT
v3.22.0.1

Long-Term Debt, Finance Leases, and Other Borrowings - Schedule of Long-term Debt (Parenthetical) (Detail) |  | 1 Months Ended | 3 Months Ended | 12 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Sep. 25, 2019 USD ($) | Dec. 31, 2021 USD ($) | Jun. 30, 2019 USD ($) Airfleet | Jan. 31, 2019 USD ($) | Feb. 28, 2018 Engine | Dec. 31, 2021 USD ($) | Dec. 31, 2020 | Sep. 30, 2021 | Sep. 30, 2016 USD ($) Air-craft | Sep. 30, 2015 USD ($) Air-craft | Nov. 14, 2020 USD ($) | Nov. 13, 2020 USD ($) | Oct. 31, 2020 USD ($) | Oct. 30, 2020 USD ($) | Sep. 30, 2019 USD ($)
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] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of aircraft financed | Air-craft |  |  |  |  |  |  |  |  |  | 7 |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  |  | $ 170,200,000 |  |  |  |  |
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] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of aircraft financed | Air-craft |  |  |  |  |  |  |  |  | 10 |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  | $ 246,000,000.0 |  |  |  |  |  |
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% |  |  |  | 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% |  |  |  | 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] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  | $ 195,300,000 |  |  |  |  |  |
Number of aircraft refinanced | Air-craft |  |  |  |  |  |  |  |  | 8 |  |  |  |  |  |
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 [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] | LIBOR [Member] | Flight Equipment [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] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of aircraft financed | Airfleet |  |  | 10 |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  | $ 70,000,000.0 |  |  |  |  |  |  |  |  |  |  |  |
Long term debt interest rate description |  |  |  |  |  | monthly LIBOR plus 5.00% |  |  |  |  |  |  |  |  |
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 |  |  | 5.00% |  |  |  |  |  |  |  |  |  |  |  |
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 [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] | LIBOR [Member] | Flight Equipment [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt, basis spread on variable rate |  |  |  |  |  | 5.00% |  |  |  |  |  |  |  |  |
Notes Payable to U.S Treasury Due 2025 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity year |  |  |  |  |  | 2025 |  | 2025 |  |  |  |  |  |  |
Notes Payable to U.S Treasury Due 2025 [Member] | Loan Agreement [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt interest rate description |  |  |  |  |  | three-month LIBOR plus 3.50% |  |  |  |  |  |  |  |  |
Long term debt, basis spread on variable rate |  |  |  |  |  | 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 |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Equipment, Due 2027 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity year |  |  |  |  |  | 2027 |  | 2027 |  |  |  |  |  |  |
Debt instrument, face amount |  | $ 30,800,000 |  |  |  | $ 30,800,000 |  |  |  |  |  |  |  |  |
Long term debt interest rate description |  |  |  |  |  | monthly LIBOR plus 4.25% |  |  |  |  |  |  |  |  |
Notes Payable to Financial Institution, Collateralized by the Underlying Equipment, Due 2027 [Member] | LIBOR [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Long term debt, basis spread on variable rate |  | 4.25% |  |  |  |  |  |  |  |  |  |  |  |  |
Senior Notes Due Two Thousand Twenty Seven [Member] | CRJ-900 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, face amount |  |  |  |  |  |  |  |  |  | $ 154,700,000 |  |  |  |  |
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% |  |  |  | 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% | one-month LIBOR plus 3.75% |  |  |  |  |  |  |  |
Term loan, term | 3 years |  |  |  |  |  |  |  |  |  |  |  |  |  |
Debt instrument, expiration year and month | 2022-09 |  |  |  |  |  |  |  |  |  |  |  |  |  |
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% |  |  |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition Debt instrument additional amount borrowed. + References No definition available. + Details
Name: | mesa_DebtInstrumentAdditionalAmountBorrowed
Namespace Prefix: | mesa_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Debt instrument amount borrowed. + References No definition available. + Details
Name: | mesa_DebtInstrumentAmountBorrowed
Namespace Prefix: | mesa_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Debt instrument, expiration month and year. + References No definition available. + Details
Name: | mesa_DebtInstrumentExpirationMonthAndYear
Namespace Prefix: | mesa_
Data Type: | xbrli:gYearMonthItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt instrument imputed interest rate. + References No definition available. + Details
Name: | mesa_DebtInstrumentImputedInterestRate
Namespace Prefix: | mesa_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Debt Instrument Maturity Year + References No definition available. + Details
Name: | mesa_DebtInstrumentMaturityYear
Namespace Prefix: | mesa_
Data Type: | xbrli:gYearItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of aircraft financed. + References No definition available. + Details
Name: | mesa_NumberOfAircraftFinanced
Namespace Prefix: | mesa_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of aircraft refinanced. + References No definition available. + Details
Name: | mesa_NumberOfAircraftRefinanced
Namespace Prefix: | mesa_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

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

X
- Definition Percentage points added to the reference rate to compute the variable rate on the debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Description of reference rate used for variable rate of debt instrument. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentDescriptionOfVariableRateBasis
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28551-108399 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=124429444&loc=SL124452920-239629 Reference 5: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69C -URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495737-112612 Reference 6: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 55 -Paragraph 69B -URI http://asc.fasb.org/extlink&oid=123466577&loc=SL123495735-112612 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 2: 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
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition 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. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Date when the debt instrument is scheduled to be fully repaid, in YYYY-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/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1B -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495323-112611 Reference 3: 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=123874694&loc=d3e19207-110258 + Details
Name: | us-gaap_DebtInstrumentMaturityDate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition 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. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after accumulated amortization, of debt discount. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=124435984&loc=d3e28541-108399 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 1D -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=123466505&loc=SL123495340-112611 + Details
Name: | us-gaap_DebtInstrumentUnamortizedDiscount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + 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 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 + Details
Name: | us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time. + 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
Name: | us-gaap_LongTermDebtPercentageBearingVariableInterestRate
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mesa_SeniorAndSubordinatedNotesPayableToSecuredPartiesCollateralizedByUnderlyingAircraftDueTwoThousandTwentySevenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_AircraftTypeAxis=srt_CRJ900Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mesa_NotesPayableToSecuredPartiesCollateralizedByUnderlyingAircraftDueTwoThousandTwentyEightMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_AircraftTypeAxis=mesa_TenE175AircraftMember
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_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mesa_SeniorAndSubordinatedNotesPayableToSecuredPartiesCollateralizedByUnderlyingAircraftDueTwoThousandTwentyEightMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_AircraftTypeAxis=mesa_EightE175AircraftMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mesa_OtherObligationsDueToFinancialInstitutionCollateralizedByUnderlyingEquipmentDueTwoThousandTwentyThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mesa_NotesPayableToFinancialInstitutionCollateralizedByTheUnderlyingEquipmentDueTwoThousandTwentyFourMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_FlightEquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VariableRateAxis=us-gaap_LondonInterbankOfferedRateLIBORMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mesa_NotesPayableToFinancialInstitutionCollateralizedByUnderlyingAircraftDueTwoThousandTwentyThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mesa_NotesPayableToFinancialInstitutionDueTwoThousandTwentyThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mesa_NotesPayableToUSTreasuryDueTwoThousandTwentyFiveMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=mesa_LoanAgreementMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mesa_NotesPayableToFinancialInstitutionCollateralizedByTheUnderlyingEquipmentDueTwoThousandTwentySevenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mesa_SeniorNotesDueTwoThousandTwentySevenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mesa_SubordinatedNotesDueTwoThousandTwentySevenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mesa_SeniorNotesDueTwoThousandTwentyEightMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mesa_SubordinatedNotesDueTwoThousandTwentyEightMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=mesa_WorkingCapitalDrawLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CreditFacilityAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |