XML 54 R44.htm IDEA: XBRL DOCUMENT
v3.20.2

Note 3 - Loans and Allowance for Loan Losses - Loans Modified as Troubled Debt Restructurings (Details) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2020 USD ($) | Jun. 30, 2019 USD ($) | Jun. 30, 2020 USD ($) | Jun. 30, 2019 USD ($)
Number of Contracts | 10 | 11 | 27 | 20
Pre- Modification Recorded Principal Balance | $ 464,000 | $ 15,822,000 | $ 11,329,000 | $ 17,003,000
Post- Modification Recorded Principal Balance | $ 465,000 | $ 16,120,000 | $ 10,726,000 | $ 17,290,000
Commercial Portfolio Segment [Member] |  |  |  |
Number of Contracts | 2 | 4 | 16 | 8
Pre- Modification Recorded Principal Balance | $ 6,000 | $ 15,607,000 | $ 10,806,000 | $ 16,686,000
Post- Modification Recorded Principal Balance | $ 6,000 | $ 15,904,000 | $ 10,201,000 | $ 16,972,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] |  |  |  |
Number of Contracts | 2 | 3 | 8 | 6
Pre- Modification Recorded Principal Balance | $ 6,000 | $ 14,040,000 | $ 6,545,000 | $ 14,429,000
Post- Modification Recorded Principal Balance | $ 6,000 | $ 14,337,000 | $ 6,542,000 | $ 14,726,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] |  |  |  |
Number of Contracts | 0 | 0 | 0 | 0
Pre- Modification Recorded Principal Balance | $ 0 | $ 0 | $ 0 | $ 0
Post- Modification Recorded Principal Balance | $ 0 | $ 0 | $ 0 | $ 0
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] |  |  |  |
Number of Contracts | 0 | 1 | 8 | 2
Pre- Modification Recorded Principal Balance | $ 0 | $ 1,567,000 | $ 4,261,000 | $ 2,257,000
Post- Modification Recorded Principal Balance | $ 0 | $ 1,567,000 | $ 3,659,000 | $ 2,246,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] |  |  |  |
Number of Contracts | 0 | 0 | 0 | 0
Pre- Modification Recorded Principal Balance | $ 0 | $ 0 | $ 0 | $ 0
Post- Modification Recorded Principal Balance | $ 0 | $ 0 | $ 0 | $ 0
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] |  |  |  |
Number of Contracts | 0 | 0 | 0 | 0
Pre- Modification Recorded Principal Balance | $ 0 | $ 0 | $ 0 | $ 0
Post- Modification Recorded Principal Balance | $ 0 | $ 0 | $ 0 | $ 0
Retail Portfolio Segment [Member] |  |  |  |
Number of Contracts | 8 | 7 | 11 | 12
Pre- Modification Recorded Principal Balance | $ 458,000 | $ 215,000 | $ 523,000 | $ 317,000
Post- Modification Recorded Principal Balance | $ 459,000 | $ 216,000 | $ 525,000 | $ 318,000
Retail Portfolio Segment [Member] | Home Equity and Other [Member] |  |  |  |
Number of Contracts | 7 | 4 | 10 | 8
Pre- Modification Recorded Principal Balance | $ 438,000 | $ 93,000 | $ 503,000 | $ 163,000
Post- Modification Recorded Principal Balance | $ 439,000 | $ 94,000 | $ 505,000 | $ 164,000
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member] |  |  |  |
Number of Contracts | 1 | 3 | 1 | 4
Pre- Modification Recorded Principal Balance | $ 20,000 | $ 122,000 | $ 20,000 | $ 154,000
Post- Modification Recorded Principal Balance | $ 20,000 | $ 122,000 | $ 20,000 | $ 154,000

X
- Definition Number of financing receivables that have been modified by troubled debt restructurings. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after troubled debt restructuring, of modified financing receivable. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount, before troubled debt restructuring, of financing receivable to be modified. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 33 -URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524 + Details
Name: | us-gaap_FinancingReceivableModificationsPreModificationRecordedInvestment2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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: |