XML 86 R73.htm IDEA: XBRL DOCUMENT
v3.22.4

Note 3 - Loans and Allowance for Loan Losses - Activity for Troubled Debt Restructurings (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] |  |  |  |  |
Beginning Balance |  | $ 4,973,000 |  | $ 6,414,000 | $ 8,587,000
Charge-Offs |  | (95,000) |  | (17,000) | 0
Payments |  | (772,000) |  | (4,278,000) | (11,260,000)
Transfers to ORE |  | 0 |  | 0 | 0
Net Additions/Deletions |  | 4,566,000 |  | 2,854,000 | 9,087,000
Ending Balance |  | 8,672,000 |  | 4,973,000 | 6,414,000
Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member] |  |  |  |  |
Beginning Balance |  | 0 |  | 0 | 85,000
Charge-Offs |  | 0 |  | 0 | 0
Payments |  | 0 |  | 0 | (85,000)
Transfers to ORE |  | 0 |  | 0 | 0
Net Additions/Deletions |  | 0 |  | 0 | 0
Ending Balance |  | 0 |  | 0 | 0
Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member] |  |  |  |  |
Beginning Balance |  | 10,435,000 |  | 14,797,000 | 1,145,000
Charge-Offs |  | (39,000) |  | 0 | 0
Payments |  | (9,683,000) |  | (5,048,000) | (3,765,000)
Transfers to ORE |  | 0 |  | 0 | 0
Net Additions/Deletions |  | (669,000) |  | 686,000 | 17,417,000
Ending Balance |  | 44,000 |  | 10,435,000 | 14,797,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] |  |  |  |  |
Beginning Balance |  | 146,000 |  | 480,000 | 178,000
Charge-Offs |  | 0 |  | 0 | 0
Payments |  | (16,000) |  | (334,000) | (585,000)
Transfers to ORE |  | 0 |  | 0 | 0
Net Additions/Deletions |  | 0 |  | 0 | 887,000
Ending Balance |  | 130,000 |  | 146,000 | 480,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] |  |  |  |  |
Beginning Balance |  | 91,000 |  | 0 | 7,000
Charge-Offs |  | 0 |  | 0 | 0
Payments |  | (91,000) |  | (1,000) | (7,000)
Transfers to ORE |  | 0 |  | 0 | 0
Net Additions/Deletions |  | 0 |  | 92,000 | 0
Ending Balance |  | 0 |  | 91,000 | 0
Retail Portfolio Segment [Member] | Other Consumer Loans [Member] |  |  |  |  |
Beginning Balance |  | 1,202,000 |  |  |
Charge-Offs |  | 0 |  |  |
Payments |  | (14,000) |  |  |
Transfers to ORE |  | 0 |  |  |
Net Additions/Deletions | [1] | (1,187,000) |  |  |
Ending Balance |  | 1,000 |  | 1,202,000 |
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member] |  |  |  |  |
Beginning Balance |  | 627,000 |  | 806,000 | 724,000
Charge-Offs |  | 0 |  | 0 | 0
Payments |  | (317,000) |  | (224,000) | (68,000)
Transfers to ORE |  | 0 |  | 0 | 0
Net Additions/Deletions |  | 2,426,000 | [1] | 45,000 | 150,000
Ending Balance |  | 2,736,000 |  | 627,000 | 806,000
Retail Portfolio Segment [Member] | Home Equity and Other [Member] |  |  |  |  |
Beginning Balance |  | $ 1,202,000 |  | 1,146,000 | 1,415,000
Charge-Offs |  |  |  | 0 | 0
Payments |  |  |  | (426,000) | (881,000)
Transfers to ORE |  |  |  | 0 | 0
Net Additions/Deletions |  |  |  | 482,000 | 612,000
Ending Balance |  |  |  | $ 1,202,000 | $ 1,146,000
[1] | Includes $1.2 million in the transfer of home equity lines of credit from other consumer loans to 1-4 family mortgages in association with the adoption of the CECL methodology effective January 1, 2022.

X
- Definition A financing receivable which had its terms modified during the period and is now considered a troubled restructuring. + References No definition available. + Details
Name: | mbwm_FinancingReceivableModifiedAsTroubledDebtRestructuringsAdditions
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Reflects the amount of the charge-off related to a troubled debt restructuring. + References No definition available. + Details
Name: | mbwm_FinancingReceivableModifiedAsTroubledDebtRestructuringsChargeOffs
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash inflow associated with a financing receivable classified as a troubled debt restructuring. + References No definition available. + Details
Name: | mbwm_FinancingReceivableModifiedAsTroubledDebtRestructuringsPayments
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The transfer of a financing receivable classified as a troubled debt restructuring to other real estate. + References No definition available. + Details
Name: | mbwm_FinancingReceivableModifiedAsTroubledDebtRestructuringsTransferToOtherRealEstate
Namespace Prefix: | mbwm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of financing receivable modified as troubled debt restructuring. + 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 https://asc.fasb.org/extlink&oid=123577603&loc=SL6953676-111524 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=121585226&loc=d3e18845-111554 + Details
Name: | us-gaap_FinancingReceivableModificationsRecordedInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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_OtherConsumerLoansMember
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_HomeEquityAndOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |