XML 42 R81.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Note 4 - Loans and Allowance for Loan Losses (Details) - Allowance Related to Troubled Debt Restructurings (USD $) | Dec. 31, 2014 | Dec. 31, 2013
--- | --- | ---
Commercial: |  |
Allowance for losses, troubled debt restructurings | $ 5,793,000 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment | $ 10,399,000 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment
Commercial and Industrial [Member] |  |
Commercial: |  |
Allowance for losses, troubled debt restructurings | 16,000 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialAndIndustrialMember | 187,000 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialAndIndustrialMember
Commercial Vacant Land and Land Development and Residential Construction Loan [Member] |  |
Commercial: |  |
Allowance for losses, troubled debt restructurings | 151,000 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember | 798,000 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialVacantLandAndLandDevelopmentAndResidentialConstructionLoanMember
Commercial Real Estate Owner Occupied Loan [Member] |  |
Commercial: |  |
Allowance for losses, troubled debt restructurings | 182,000 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember | 528,000 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateOwnerOccupiedLoanMember
Commercial Real Estate Non Owner Occupied Loan [Member] |  |
Commercial: |  |
Allowance for losses, troubled debt restructurings | 4,778,000 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember | 7,828,000 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateNonOwnerOccupiedLoanMember
Commercial Real Estate Multi Family and Residential Rental Loan [Member] |  |
Commercial: |  |
Allowance for losses, troubled debt restructurings | 666,000 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember | 1,010,000 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_CommercialRealEstateMultiFamilyAndResidentialRentalLoanMember
Commercial Portfolio Segment [Member] |  |
Commercial: |  |
Allowance for losses, troubled debt restructurings | 5,793,000 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialPortfolioSegmentMember | 10,351,000 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = us-gaap_CommercialPortfolioSegmentMember
Retail Home Equity and Other [Member] |  |
Commercial: |  |
Allowance for losses, troubled debt restructurings | 0 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_RetailHomeEquityAndOtherMember | 0 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_RetailHomeEquityAndOtherMember
Retail 1-4 Family Mortgages [Member] |  |
Commercial: |  |
Allowance for losses, troubled debt restructurings | 0 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_Retail1To4FamilyMortgagesMember | 48,000 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_Retail1To4FamilyMortgagesMember
Retail Loan [Member] |  |
Commercial: |  |
Allowance for losses, troubled debt restructurings | $ 0 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_RetailLoanMember | $ 48,000 us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment / us-gaap_FinancingReceivableTroubledDebtRestructuringAxis = mbwm_RetailLoanMember

X
- Details
Name: | mbwm_CommercialAbstract0000000000000000000
Namespace Prefix: | mbwm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of allowance for credit losses related to receivables which had been measured under a general allowance for credit losses methodology that are now identified as troubled debt restructurings. + References No definition available. + Details
Name: | us-gaap_AllowanceForCreditLossesChangeInMethodOfCalculatingImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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

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

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

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

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

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

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

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

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