XML 36 R73.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Note 4 - Loans and Allowance for Loan Losses (Details) - Age Analysis of Past Due Loans (USD $) | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
--- | --- | --- | ---
Commercial: |  |  |
Loans | $ 2,089,277,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome | $ 1,053,243,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome | $ 1,041,189,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
Originated Loan [Member] | Commercial and Industrial [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 0 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember | 0 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember |
Loans- 60 to 89 days past due | 0 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember | 0 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember |
Loans- Greater than 89 days past due | 0 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember | 309,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember |
Loans- Total past due | 0 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember | 309,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember |
Loans- Current | 384,570,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember | 286,064,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember |
Loans | 384,570,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember | 286,373,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember |
Originated Loan [Member] | Commercial Vacant Land and Land Development and Residential Construction Loan [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 0 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |
Loans- 60 to 89 days past due | 0 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |
Loans- Greater than 89 days past due | 0 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |
Loans- Total past due | 0 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |
Loans- Current | 29,826,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember | 36,741,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |
Loans | 29,826,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember | 36,741,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |
Originated Loan [Member] | Commercial Real Estate Owner Occupied Loan [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 0 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember | 65,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |
Loans- 60 to 89 days past due | 0 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |
Loans- Greater than 89 days past due | 120,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember | 50,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |
Loans- Total past due | 120,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember | 115,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |
Loans- Current | 291,638,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember | 261,762,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |
Loans | 291,758,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember | 261,877,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |
Originated Loan [Member] | Commercial Real Estate Non Owner Occupied Loan [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 0 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |
Loans- 60 to 89 days past due | 0 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |
Loans- Greater than 89 days past due | 116,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |
Loans- Total past due | 116,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |
Loans- Current | 410,861,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember | 364,066,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |
Loans | 410,977,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember | 364,066,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |
Originated Loan [Member] | Commercial Real Estate Multi Family and Residential Rental Loan [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 0 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |
Loans- 60 to 89 days past due | 0 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |
Loans- Greater than 89 days past due | 0 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember | 64,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |
Loans- Total past due | 0 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember | 64,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |
Loans- Current | 36,058,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember | 37,575,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |
Loans | 36,058,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember | 37,639,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |
Originated Loan [Member] | Commercial Portfolio Segment [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 0 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember | 65,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember |
Loans- 60 to 89 days past due | 0 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember | 0 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember |
Loans- Greater than 89 days past due | 236,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember | 423,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember |
Loans- Total past due | 236,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember | 488,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember |
Loans- Current | 1,152,953,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember | 986,208,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember |
Loans | 1,153,189,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember | 986,696,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember |
Originated Loan [Member] | Retail Home Equity and Other [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 38,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember | 14,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember |
Loans- 60 to 89 days past due | 3,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember | 0 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember |
Loans- Greater than 89 days past due | 0 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember | 0 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember |
Loans- Total past due | 41,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember | 14,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember |
Loans- Current | 50,018,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember | 35,066,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember |
Loans | 50,059,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember | 35,080,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember |
Originated Loan [Member] | Retail 1-4 Family Mortgages [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 0 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember | 21,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember |
Loans- 60 to 89 days past due | 0 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember | 44,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember |
Loans- Greater than 89 days past due | 366,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember | 375,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember |
Loans- Total past due | 366,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember | 440,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember |
Loans- Current | 42,502,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember | 31,027,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember |
Loans | 42,868,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember | 31,467,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember |
Originated Loan [Member] | Retail Loan [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 38,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember | 35,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember |
Loans- 60 to 89 days past due | 3,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember | 44,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember |
Loans- Greater than 89 days past due | 366,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember | 375,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember |
Loans- Total past due | 407,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember | 454,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember |
Loans- Current | 92,520,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember | 66,093,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember |
Loans | 92,927,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember | 66,547,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember |
Originated Loan [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 38,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember | 100,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember |
Loans- 60 to 89 days past due | 3,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember | 44,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember |
Loans- Greater than 89 days past due | 602,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember | 798,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember |
Loans- Total past due | 643,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember | 942,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember |
Loans- Current | 1,245,473,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember | 1,052,301,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember |
Loans | 1,246,116,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember | 1,053,243,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_OriginatedLoanMember |
Acquired Loan [Member] | Commercial and Industrial [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 29,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember |  |
Loans- 60 to 89 days past due | 32,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember |  |
Loans- Greater than 89 days past due | 76,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember |  |
Loans- Total past due | 137,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember |  |
Loans- Current | 165,900,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember |  |
Loans | 166,037,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember | 0 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember |  |
Acquired Loan [Member] | Commercial Vacant Land and Land Development and Residential Construction Loan [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 0 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |  |
Loans- 60 to 89 days past due | 38,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |  |
Loans- Greater than 89 days past due | 0 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |  |
Loans- Total past due | 38,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |  |
Loans- Current | 22,110,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |  |
Loans | 22,148,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember | 0 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |  |
Acquired Loan [Member] | Commercial Real Estate Owner Occupied Loan [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 51,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |  |
Loans- 60 to 89 days past due | 425,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |  |
Loans- Greater than 89 days past due | 1,625,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |  |
Loans- Total past due | 2,101,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |  |
Loans- Current | 136,529,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |  |
Loans | 138,630,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember | 0 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |  |
Acquired Loan [Member] | Commercial Real Estate Non Owner Occupied Loan [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 68,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |  |
Loans- 60 to 89 days past due | 598,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |  |
Loans- Greater than 89 days past due | 395,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |  |
Loans- Total past due | 1,061,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |  |
Loans- Current | 147,536,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |  |
Loans | 148,597,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember | 0 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |  |
Acquired Loan [Member] | Commercial Real Estate Multi Family and Residential Rental Loan [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 37,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |  |
Loans- 60 to 89 days past due | 0 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |  |
Loans- Greater than 89 days past due | 105,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |  |
Loans- Total past due | 142,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |  |
Loans- Current | 86,560,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |  |
Loans | 86,702,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember | 0 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |  |
Acquired Loan [Member] | Commercial Portfolio Segment [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 185,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember |  |
Loans- 60 to 89 days past due | 1,093,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember |  |
Loans- Greater than 89 days past due | 2,201,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember |  |
Loans- Total past due | 3,479,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember |  |
Loans- Current | 558,635,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember |  |
Loans | 562,114,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember | 0 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember |  |
Acquired Loan [Member] | Retail Home Equity and Other [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 445,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember |  |
Loans- 60 to 89 days past due | 419,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember |  |
Loans- Greater than 89 days past due | 155,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember |  |
Loans- Total past due | 1,019,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember |  |
Loans- Current | 108,200,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember |  |
Loans | 109,219,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember | 0 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember |
Loans- Recorded Balance >89days and accruing | 26,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember |  |
Acquired Loan [Member] | Retail 1-4 Family Mortgages [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 1,087,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember |  |
Loans- 60 to 89 days past due | 408,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember |  |
Loans- Greater than 89 days past due | 750,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember |  |
Loans- Total past due | 2,245,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember |  |
Loans- Current | 169,583,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember |  |
Loans | 171,828,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember | 0 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember |
Loans- Recorded Balance >89days and accruing | 0 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember |  |
Acquired Loan [Member] | Retail Loan [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 1,532,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember |  |
Loans- 60 to 89 days past due | 827,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember |  |
Loans- Greater than 89 days past due | 905,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember |  |
Loans- Total past due | 3,264,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember |  |
Loans- Current | 277,783,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember |  |
Loans | 281,047,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember | 0 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember |
Loans- Recorded Balance >89days and accruing | 26,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember |  |
Acquired Loan [Member] |  |  |
Commercial: |  |  |
Loans- 30 to 59 days past due | 1,717,000 us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember |  |
Loans- 60 to 89 days past due | 1,920,000 us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember |  |
Loans- Greater than 89 days past due | 3,106,000 us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember |  |
Loans- Total past due | 6,743,000 us-gaap_FinancingReceivableRecordedInvestmentPastDue / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember |  |
Loans- Current | 836,418,000 us-gaap_FinancingReceivableRecordedInvestmentCurrent / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember |  |
Loans | 843,161,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember | 0 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember |
Loans- Recorded Balance >89days and accruing | 26,000 us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing / us-gaap_FinancialInstrumentAxis = mbwm_AcquiredLoanMember |  |
Commercial and Industrial [Member] |  |  |
Commercial: |  |  |
Loans | 550,607,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember | 286,373,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialAndIndustrialMember |
Commercial Vacant Land and Land Development and Residential Construction Loan [Member] |  |  |
Commercial: |  |  |
Loans | 51,974,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember | 36,741,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember |
Commercial Real Estate Owner Occupied Loan [Member] |  |  |
Commercial: |  |  |
Loans | 430,388,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember | 261,877,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember |
Commercial Real Estate Non Owner Occupied Loan [Member] |  |  |
Commercial: |  |  |
Loans | 559,574,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember | 364,066,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember |
Commercial Real Estate Multi Family and Residential Rental Loan [Member] |  |  |
Commercial: |  |  |
Loans | 122,760,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember | 37,639,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember |
Commercial Portfolio Segment [Member] |  |  |
Commercial: |  |  |
Loans | 1,715,303,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember | 986,696,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember | 968,506,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = us-gaap_CommercialPortfolioSegmentMember
Retail Home Equity and Other [Member] |  |  |
Commercial: |  |  |
Loans | 159,278,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember | 35,080,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailHomeEquityAndOtherMember |
Retail 1-4 Family Mortgages [Member] |  |  |
Commercial: |  |  |
Loans | 214,696,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember | 31,467,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_Retail1To4FamilyMortgagesMember |
Retail Loan [Member] |  |  |
Commercial: |  |  |
Loans | $ 373,974,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember | $ 66,547,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember | $ 72,683,000 us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome / us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis = mbwm_RetailLoanMember

X
- Details
Name: | mbwm_CommercialAbstract0000
Namespace Prefix: | mbwm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Financing receivables that are less than 60 days past due but more than 29 days past due. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7A -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953401-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestment30To59DaysPastDue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financing receivables that are less than 90 days past due but more than 59 days past due. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7A -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953401-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestment60To89DaysPastDue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Recorded investment in financing receivables that are 90 days or more past due and still accruing. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5111-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financing receivables that are current. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7A -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953401-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Financing receivables that are equal to or greater than 90 days past due. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7A -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953401-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentEqualToGreaterThan90DaysPastDue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Recorded Investment in financing receivables that are past due at the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7A -URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953401-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentPastDue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes 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 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5074-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=28367877&loc=d3e4428-111522 + Details
Name: | us-gaap_LoansAndLeasesReceivableNetOfDeferredIncome
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=mbwm_AcquiredLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=mbwm_OriginatedLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mbwm_CommercialAndIndustrialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mbwm_CommercialRealEstateOwnerOccupiedLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mbwm_Retail1To4FamilyMortgagesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mbwm_RetailHomeEquityAndOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=mbwm_RetailLoanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |