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Note 4 - Loans and Related Allowance for Loan Losses (Details) - Allowance for Loan Losses (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Sep. 30, 2014 | Jun. 30, 2014 | Mar. 31, 2014 | Dec. 31, 2013 | Sep. 30, 2013 | Jun. 30, 2013 | Mar. 31, 2013 | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011
Ending allowance balance attributable to loans: |  |  |  |  |  |  |  |  |  |  |
Individually evaluated for impairment |  |  |  | $ 1,807 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 |  |  |  | $ 1,596 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 | $ 1,807 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 |  |
Collectively evaluated for impairment |  |  |  | 5,239 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment |  |  |  | 5,250 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment | 5,239 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment |  |
Balance |  |  |  | 7,046 us-gaap_LoansAndLeasesReceivableAllowance |  |  |  | 6,846 us-gaap_LoansAndLeasesReceivableAllowance | 7,046 us-gaap_LoansAndLeasesReceivableAllowance | 7,779 us-gaap_LoansAndLeasesReceivableAllowance | 6,819 us-gaap_LoansAndLeasesReceivableAllowance
Charge-offs |  |  |  |  |  |  |  | (1,212)us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs | (1,330)us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs | (1,337)us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs |
Recoveries |  |  |  |  |  |  |  | 642 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts | 401 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts | 129 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts |
Provision | 70 us-gaap_ProvisionForLoanAndLeaseLosses | 120 us-gaap_ProvisionForLoanAndLeaseLosses | 180 us-gaap_ProvisionForLoanAndLeaseLosses | (570)us-gaap_ProvisionForLoanAndLeaseLosses | 153 us-gaap_ProvisionForLoanAndLeaseLosses | 300 us-gaap_ProvisionForLoanAndLeaseLosses | 313 us-gaap_ProvisionForLoanAndLeaseLosses | 370 us-gaap_ProvisionForLoanAndLeaseLosses | 196 us-gaap_ProvisionForLoanAndLeaseLosses | 2,168 us-gaap_ProvisionForLoanAndLeaseLosses |
Commercial and Industrial [Member] |  |  |  |  |  |  |  |  |  |  |
Ending allowance balance attributable to loans: |  |  |  |  |  |  |  |  |  |  |
Individually evaluated for impairment |  |  |  | 179 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember |  |  |  | 83 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember | 179 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember |  |
Collectively evaluated for impairment |  |  |  | 435 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember |  |  |  | 559 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember | 435 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember |  |
Balance |  |  |  | 614 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember |  |  |  | 642 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember | 614 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember | 1,732 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember | 1,296 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember
Charge-offs |  |  |  |  |  |  |  | (237)us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember | (419)us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember | (230)us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember |
Recoveries |  |  |  |  |  |  |  | 121 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember | 191 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember | 71 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember |
Provision |  |  |  |  |  |  |  | 144 us-gaap_ProvisionForLoanAndLeaseLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember | (890)us-gaap_ProvisionForLoanAndLeaseLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember | 595 us-gaap_ProvisionForLoanAndLeaseLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialAndIndustrialMember |
Real Estate Construction [Member] |  |  |  |  |  |  |  |  |  |  |
Ending allowance balance attributable to loans: |  |  |  |  |  |  |  |  |  |  |
Individually evaluated for impairment |  |  |  | 210 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember |  |  |  | 589 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember | 210 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember |  |
Collectively evaluated for impairment |  |  |  | 366 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember |  |  |  | 279 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember | 366 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember |  |
Balance |  |  |  | 576 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember |  |  |  | 868 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember | 576 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember | 1,123 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember | 438 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember
Charge-offs |  |  |  |  |  |  |  |  | (191)us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember | (135)us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember |
Recoveries |  |  |  |  |  |  |  | 60 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember | 33 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember |  |
Provision |  |  |  |  |  |  |  | 232 us-gaap_ProvisionForLoanAndLeaseLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember | (389)us-gaap_ProvisionForLoanAndLeaseLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember | 820 us-gaap_ProvisionForLoanAndLeaseLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_RealEstateConstructionMember |
Residential Real Estate Mortgage [Member] |  |  |  |  |  |  |  |  |  |  |
Ending allowance balance attributable to loans: |  |  |  |  |  |  |  |  |  |  |
Individually evaluated for impairment |  |  |  | 855 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember |  |  |  | 892 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember | 855 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember |  |
Collectively evaluated for impairment |  |  |  | 2,809 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember |  |  |  | 2,811 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember | 2,809 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember |  |
Balance |  |  |  | 3,664 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember |  |  |  | 3,703 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember | 3,664 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember | 2,872 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember | 3,731 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember
Charge-offs |  |  |  |  |  |  |  | (671)us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember | (675)us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember | (785)us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember |
Recoveries |  |  |  |  |  |  |  | 267 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember | 107 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember | 31 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember |
Provision |  |  |  |  |  |  |  | 443 us-gaap_ProvisionForLoanAndLeaseLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember | 1,360 us-gaap_ProvisionForLoanAndLeaseLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember | (105)us-gaap_ProvisionForLoanAndLeaseLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ResidentialRealEstateMortgageMember |
Commercial Real Estate Mortgage [Member] |  |  |  |  |  |  |  |  |  |  |
Ending allowance balance attributable to loans: |  |  |  |  |  |  |  |  |  |  |
Individually evaluated for impairment |  |  |  | 563 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember |  |  |  | 30 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember | 563 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember |  |
Collectively evaluated for impairment |  |  |  | 1,607 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember |  |  |  | 1,546 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember | 1,607 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember |  |
Balance |  |  |  | 2,170 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember |  |  |  | 1,576 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember | 2,170 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember | 1,991 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember | 1,306 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember
Charge-offs |  |  |  |  |  |  |  | (260)us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember |  | (123)us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember |
Recoveries |  |  |  |  |  |  |  | 40 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember | 46 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember |  |
Provision |  |  |  |  |  |  |  | (374)us-gaap_ProvisionForLoanAndLeaseLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember | 133 us-gaap_ProvisionForLoanAndLeaseLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember | 808 us-gaap_ProvisionForLoanAndLeaseLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_CommercialRealEstateMortgageMember |
Consumer Installment [Member] |  |  |  |  |  |  |  |  |  |  |
Ending allowance balance attributable to loans: |  |  |  |  |  |  |  |  |  |  |
Individually evaluated for impairment |  |  |  |  |  |  |  | 2 us-gaap_FinancingReceivableAllowanceForCreditLossesIndividuallyEvaluatedForImpairment1 / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember |  |  |
Collectively evaluated for impairment |  |  |  | 22 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember |  |  |  | 55 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember | 22 us-gaap_FinancingReceivableAllowanceForCreditLossesCollectivelyEvaluatedForImpairment / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember |  |
Balance |  |  |  | 22 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember |  |  |  | 57 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember | 22 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember | 61 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember | 48 us-gaap_LoansAndLeasesReceivableAllowance / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember
Charge-offs |  |  |  |  |  |  |  | (44)us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember | (45)us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember | (64)us-gaap_AllowanceForLoanAndLeaseLossesWriteOffs / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember |
Recoveries |  |  |  |  |  |  |  | 154 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember | 24 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember | 27 us-gaap_AllowanceForLoanAndLeaseLossRecoveryOfBadDebts / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember |
Provision |  |  |  |  |  |  |  | $ (75)us-gaap_ProvisionForLoanAndLeaseLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember | $ (18)us-gaap_ProvisionForLoanAndLeaseLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember | $ 50 us-gaap_ProvisionForLoanAndLeaseLosses / us-gaap_AccountsNotesLoansAndFinancingReceivableByReceivableTypeAxis = mbcn_ConsumerInstallmentMember |

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- Definition Amount of loans and leases that have been written off from both loan receivables and allowance reserve for credit loss. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7(d)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph d -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(3) -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524 + Details
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- Definition Amount of recovery of loans and lease receivables which had previously been fully or partially written-off as bad debts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(4) -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524 + Details
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- Definition The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524 + Details
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- Definition Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524 + Details
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- Definition Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7(d)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph d -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (b)(1)(ii) -URI http://asc.fasb.org/extlink&oid=6379141&loc=d3e15032-111544 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 6 -Section L -Subsection 1 + Details
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