XML 38 R40.htm IDEA: XBRL DOCUMENT
v3.3.0.814

Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans - USD ($) | Sep. 30, 2015 | Dec. 31, 2014
--- | --- | ---
Nonperforming Financial Instruments [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Nonperforming loans | $ 8,214,000 | $ 29,432,000
Originated Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Originated Loan [Member] | Nonperforming Financial Instruments [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Nonaccrual loans | 2,590,000 | 26,048,000
Nonperforming loans | 2,590,000 | 26,048,000
Acquired Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 26,000
Acquired Loan [Member] | Nonperforming Financial Instruments [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 43,000 | 26,000
Nonaccrual loans | 5,581,000 | 3,358,000
Nonperforming loans | 5,624,000 | 3,384,000
Commercial Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Nonperforming loans | 5,647,000 | 25,233,000
Commercial Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | Commercial and Industrial [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Nonperforming loans | 671,000 | 6,478,000
Commercial Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Nonperforming loans | 170,000 | 209,000
Commercial Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | Real Estate Owner Occupied Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Nonperforming loans | 2,262,000 | 18,062,000
Commercial Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | Real Estate Non Owner Occupied Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Nonperforming loans | 79,000 | 378,000
Commercial Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | Real Estate Multi Family and Residential Rental Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Nonperforming loans | 2,465,000 | 106,000
Commercial Portfolio Segment [Member] | Originated Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Commercial and Industrial [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Owner Occupied Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Non Owner Occupied Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Commercial Portfolio Segment [Member] | Originated Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Commercial and Industrial [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Owner Occupied Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Non Owner Occupied Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Commercial Portfolio Segment [Member] | Acquired Loan [Member] | Real Estate Multi Family and Residential Rental Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Retail Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Nonperforming loans | 2,567,000 | 4,199,000
Retail Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | Home Equity and Other [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Nonperforming loans | 749,000 | 800,000
Retail Portfolio Segment [Member] | Nonperforming Financial Instruments [Member] | 1-4 Family Mortgages [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Nonperforming loans | 1,818,000 | 3,399,000
Retail Portfolio Segment [Member] | Originated Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Retail Portfolio Segment [Member] | Originated Loan [Member] | Home Equity and Other [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Retail Portfolio Segment [Member] | Originated Loan [Member] | 1-4 Family Mortgages [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 0
Retail Portfolio Segment [Member] | Acquired Loan [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 26,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | Home Equity and Other [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | 0 | 26,000
Retail Portfolio Segment [Member] | Acquired Loan [Member] | 1-4 Family Mortgages [Member] |  |
Note 3 - Loans and Allowance for Loan Losses (Details) - Nonperforming Loans [Line Items] |  |
Loans past due 90 days or more still accruing interest | $ 0 | $ 0

X
- Definition Amount of financing receivables which are past due 90 days or more and still accruing interest and nonaccrual loans. + References No definition available. + Details
Name: | mbwm_FinancingReceivablePastDueNinetyDaysOrMoreAndStillAccruingInterestAndNonaccrualLoans
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | mbwm_Note3LoansandAllowanceforLoanLossesDetailsNonperformingLoansLineItems
Namespace Prefix: | mbwm_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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=49124121&loc=d3e5111-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Recorded investment in financing receivables that are on nonaccrual status as of 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 7 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5111-111524 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentNonaccrualStatus
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

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

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

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

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

X
- Details
Name: | us-gaap_FinancingReceivablePortfolioSegmentAxis=mbwm_RetailPortfolioSegmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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