XML 77 R64.htm IDEA: XBRL DOCUMENT
v3.22.4

Note 3 - Loans and Allowance for Credit Losses - Age Analysis of Past Due Loans (Details) - USD ($) | Dec. 31, 2022 | Dec. 31, 2021
--- | --- | ---
Financing Receivable, before Allowance for Credit Loss, Total |  | $ 3,916,619,000 | $ 3,453,459,000
Loans past due 90 days or more still accruing interest |  | 0 | 155,000
Financial Asset, 30 to 59 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 1,349,000 | 1,424,000
Financial Asset, 60 to 89 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 6,042,000 | 243,000
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 365,000 | 295,000
Financial Asset, Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 7,756,000 | 1,962,000
Financial Asset, Not Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 3,908,863,000 | 3,451,497,000
Commercial Portfolio Segment [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 3,131,830,000 | 2,950,424,000
Loans past due 90 days or more still accruing interest |  | 0 | 155,000
Commercial Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 27,000
Commercial Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 5,953,000 | 0
Commercial Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 249,000 | 193,000
Commercial Portfolio Segment [Member] | Financial Asset, Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 6,202,000 | 220,000
Commercial Portfolio Segment [Member] | Financial Asset, Not Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 3,125,628,000 | 2,950,204,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total | [1] | 1,185,083,000 | 1,137,419,000
Loans past due 90 days or more still accruing interest |  | 0 | 155,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Financial Asset, 30 to 59 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 14,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Financial Asset, 60 to 89 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 5,705,000 | 0
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 249,000 | 193,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Financial Asset, Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 5,954,000 | 207,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] | Financial Asset, Not Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 1,179,129,000 | 1,137,212,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 61,873,000 | 43,239,000
Loans past due 90 days or more still accruing interest |  | 0 | 0
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Financial Asset, 30 to 59 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 13,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Financial Asset, 60 to 89 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 0
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 0
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Financial Asset, Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 13,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] | Financial Asset, Not Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 61,873,000 | 43,226,000
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 639,192,000 | 565,758,000
Loans past due 90 days or more still accruing interest |  | 0 | 0
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Financial Asset, 30 to 59 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 0
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Financial Asset, 60 to 89 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 248,000 | 0
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 0
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Financial Asset, Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 248,000 | 0
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] | Financial Asset, Not Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 638,944,000 | 565,758,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 1,033,734,000 | 1,027,415,000
Loans past due 90 days or more still accruing interest |  | 0 | 0
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Financial Asset, 30 to 59 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 0
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Financial Asset, 60 to 89 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 0
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 0
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Financial Asset, Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 0
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] | Financial Asset, Not Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 1,033,734,000 | 1,027,415,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 211,948,000 | 176,593,000
Loans past due 90 days or more still accruing interest |  | 0 | 0
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Financial Asset, 30 to 59 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 0
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Financial Asset, 60 to 89 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 0
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 0
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Financial Asset, Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 0
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] | Financial Asset, Not Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 211,948,000 | 176,593,000
Retail Portfolio Segment [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 784,789,000 | 503,035,000
Loans past due 90 days or more still accruing interest |  | 0 | 0
Retail Portfolio Segment [Member] | Financial Asset, 30 to 59 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 1,349,000 | 1,397,000
Retail Portfolio Segment [Member] | Financial Asset, 60 to 89 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 89,000 | 243,000
Retail Portfolio Segment [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 116,000 | 102,000
Retail Portfolio Segment [Member] | Financial Asset, Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 1,554,000 | 1,742,000
Retail Portfolio Segment [Member] | Financial Asset, Not Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 783,235,000 | 501,293,000
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 755,036,000 | 442,547,000
Loans past due 90 days or more still accruing interest |  | 0 | 0
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member] | Financial Asset, 30 to 59 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 1,334,000 | 1,265,000
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member] | Financial Asset, 60 to 89 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 88,000 | 241,000
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 116,000 | 82,000
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member] | Financial Asset, Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 1,538,000 | 1,588,000
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member] | Financial Asset, Not Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 753,498,000 | 440,959,000
Retail Portfolio Segment [Member] | Other Consumer Loans [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total | [2] | 29,753,000 | 60,488,000
Loans past due 90 days or more still accruing interest |  | 0 | 0
Retail Portfolio Segment [Member] | Other Consumer Loans [Member] | Financial Asset, 30 to 59 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 15,000 | 132,000
Retail Portfolio Segment [Member] | Other Consumer Loans [Member] | Financial Asset, 60 to 89 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 1,000 | 2,000
Retail Portfolio Segment [Member] | Other Consumer Loans [Member] | Financial Asset, Equal to or Greater than 90 Days Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 0 | 20,000
Retail Portfolio Segment [Member] | Other Consumer Loans [Member] | Financial Asset, Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | 16,000 | 154,000
Retail Portfolio Segment [Member] | Other Consumer Loans [Member] | Financial Asset, Not Past Due [Member] |  |  |
Financing Receivable, before Allowance for Credit Loss, Total |  | $ 29,737,000 | $ 60,334,000
[1] | For December 31, 2022, and December 31, 2021, includes $0.9 million and $40.1 million in loans originated under the Paycheck Protection Program, respectively.
[2] | In conjunction with the adoption of the CECL methodology effective January 1, 2022, home equity lines of credit were reclassified to 1-4 family mortgage loans from other consumer loans. Home equity lines of credit totaled $37.4 million and $29.5 million as of December 31, 2022, and 2021, respectively.

X
- Definition Amortized cost of financing receivable 90 days or more past due and still accruing. Excludes net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 16 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919258-210447 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=123577603&loc=d3e5111-111524 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 80 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922355-210448 + Details
Name: | us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amortized cost, before allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement and net investment in lease. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 7A -URI https://asc.fasb.org/extlink&oid=123577603&loc=SL6953401-111524 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 79 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922352-210448 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(3)(b)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 14 -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919253-210447 Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 45 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=124255206&loc=SL82895884-210446 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=124255953&loc=SL82919230-210447 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 55 -Paragraph 80 -URI https://asc.fasb.org/extlink&oid=124267575&loc=SL82922355-210448 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher SEC -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (a) -Subparagraph (1) Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher SEC -Name Regulation S-K (SK) -Number 229 -Section 1405 -Paragraph (a) -Subparagraph (2) Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher SEC -Name Regulation S-K (SK) -Number 229 -Section 1404 -Paragraph (a) + Details
Name: | us-gaap_NotesReceivableGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables30To59DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivables60To89DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancingReceivablesEqualToGreaterThan90DaysPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancialAssetPastDueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivablesPeriodPastDueAxis=us-gaap_FinancialAssetNotPastDueMember
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_OneToFourFamilyMortgagesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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