XML 80 R61.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Note 5 - Fair Value Measurements - Additional Quantitative Information About Assets Measured at Fair Value on Non-recurring Basis (Details) - Fair Value, Nonrecurring [Member] - Fair Value, Inputs, Level 3 [Member] - Appraisal of Collateral [Member] $ in Thousands | Dec. 31, 2024 USD ($) | Dec. 31, 2023 USD ($)
--- | --- | ---
Collateral-dependent loans | $ 3,321 | $ 3,361
Measurement Input, Appraised Value [Member] | Minimum [Member] |  |
Collateral-dependent loans, range |  | 0.201
Measurement Input, Appraised Value [Member] | Weighted Average [Member] |  |
Collateral-dependent loans, range | 0.239 |

X
- Definition Value of input used to measure impaired loans. + References No definition available. + Details
Name: | mbcn_ImpairedLoansMeasurementInput
Namespace Prefix: | mbcn_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fair value of impaired loans receivable. + References No definition available. + Details
Name: | mbcn_ImpairedLoansReceivableFairValueDisclosure
Namespace Prefix: | mbcn_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ValuationTechniqueAxis=mbcn_AppraisalOfCollateralMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MeasurementInputTypeAxis=us-gaap_MeasurementInputAppraisedValueMember
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_WeightedAverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |