XML 32 R79.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due (USD $) | 12 Months Ended | 7 Months Ended
--- | --- | ---
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2014
Commercial and Industrial [Member] | Originated Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialAndIndustrialMember | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialAndIndustrialMember |
Recorded principal balance | $ 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialAndIndustrialMember | $ 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialAndIndustrialMember |
Commercial and Industrial [Member] | Acquired Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialAndIndustrialMember
Recorded principal balance |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialAndIndustrialMember
Commercial Vacant Land and Land Development and Residential Construction Loan [Member] | Originated Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |
Recorded principal balance | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |
Commercial Vacant Land and Land Development and Residential Construction Loan [Member] | Acquired Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember
Recorded principal balance |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember
Commercial Real Estate Owner Occupied Loan [Member] | Originated Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember | 1 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |
Recorded principal balance | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember | 65,000 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |
Commercial Real Estate Owner Occupied Loan [Member] | Acquired Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember
Recorded principal balance |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember
Commercial Real Estate Non Owner Occupied Loan [Member] | Originated Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |
Recorded principal balance | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |
Commercial Real Estate Non Owner Occupied Loan [Member] | Acquired Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember
Recorded principal balance |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember
Commercial Real Estate Multi Family and Residential Rental Loan [Member] | Originated Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |
Recorded principal balance | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |
Commercial Real Estate Multi Family and Residential Rental Loan [Member] | Acquired Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember
Recorded principal balance |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember
Commercial Portfolio Segment [Member] | Originated Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialPortfolioSegmentMember | 1 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialPortfolioSegmentMember |
Recorded principal balance | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialPortfolioSegmentMember | 65,000 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialPortfolioSegmentMember |
Commercial Portfolio Segment [Member] | Acquired Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialPortfolioSegmentMember
Recorded principal balance |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialPortfolioSegmentMember
Retail Home Equity and Other [Member] | Originated Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_RetailHomeEquityAndOtherMember | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_RetailHomeEquityAndOtherMember |
Recorded principal balance | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_RetailHomeEquityAndOtherMember | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_RetailHomeEquityAndOtherMember |
Retail Home Equity and Other [Member] | Acquired Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_RetailHomeEquityAndOtherMember
Recorded principal balance |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_RetailHomeEquityAndOtherMember
Retail 1-4 Family Mortgages [Member] | Originated Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_Retail1To4FamilyMortgagesMember | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_Retail1To4FamilyMortgagesMember |
Recorded principal balance | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_Retail1To4FamilyMortgagesMember | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_Retail1To4FamilyMortgagesMember |
Retail 1-4 Family Mortgages [Member] | Acquired Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_Retail1To4FamilyMortgagesMember
Recorded principal balance |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_Retail1To4FamilyMortgagesMember
Retail Loan [Member] | Originated Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_RetailLoanMember | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_RetailLoanMember |
Recorded principal balance | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_RetailLoanMember | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_RetailLoanMember |
Retail Loan [Member] | Acquired Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_RetailLoanMember
Recorded principal balance |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_RetailLoanMember
Originated Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember | 1 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember |
Recorded principal balance | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember | 65,000 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember |
Acquired Loan [Member] |  |  |
Note 4 - Loans and Allowance for Loan Losses (Details) - Loans Modified as Troubled Debt Restructurings within the Previous Twelve Months That Became Over 30 Days Past Due [Line Items] |  |  |
Number of contracts |  |  | 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultNumberOfContracts1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember
Recorded principal balance |  |  | $ 0 us-gaap_FinancingReceivableModificationsSubsequentDefaultRecordedInvestment1 / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember

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- Definition Number of financing receivables that have been modified by troubled debt restructurings within the previous 12 months and for which there was a payment default. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953682-111524 + Details
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- Definition Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 34 -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953682-111524 + Details
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