XML 56 R46.htm IDEA: XBRL DOCUMENT
v3.21.2

Note 3 - Loans and Allowance for Loan Losses - Loans Modified as Troubled Debt Restructurings (Details) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2021 USD ($) | Sep. 30, 2020 USD ($) | Sep. 30, 2021 USD ($) | Sep. 30, 2020 USD ($)
Number of Contracts | 3 | 12 | 18 | 34
Pre- Modification Recorded Principal Balance | $ 279,000 | $ 784,000 | $ 4,333,000 | $ 11,074,000
Post- Modification Recorded Principal Balance | $ 278,000 | $ 784,000 | $ 4,329,000 | $ 10,478,000
Commercial Portfolio Segment [Member] |  |  |  |
Number of Contracts | 3 | 5 | 12 | 17
Pre- Modification Recorded Principal Balance | $ 279,000 | $ 634,000 | $ 3,802,000 | $ 10,564,000
Post- Modification Recorded Principal Balance | $ 278,000 | $ 634,000 | $ 3,801,000 | $ 9,968,000
Commercial Portfolio Segment [Member] | Commercial and Industrial [Member] |  |  |  |
Number of Contracts | 2 | 2 | 10 | 8
Pre- Modification Recorded Principal Balance | $ 186,000 | $ 7,000 | $ 3,017,000 | $ 6,485,000
Post- Modification Recorded Principal Balance | $ 185,000 | $ 7,000 | $ 3,016,000 | $ 6,491,000
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 | 1 | 7
Pre- Modification Recorded Principal Balance | $ 0 | $ 56,000 | $ 692,000 | $ 3,508,000
Post- Modification Recorded Principal Balance | $ 0 | $ 56,000 | $ 692,000 | $ 2,906,000
Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member] |  |  |  |
Number of Contracts | 0 | 2 | 0 | 2
Pre- Modification Recorded Principal Balance | $ 0 | $ 571,000 | $ 0 | $ 571,000
Post- Modification Recorded Principal Balance | $ 0 | $ 571,000 | $ 0 | $ 571,000
Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member] |  |  |  |
Number of Contracts | 1 | 0 | 1 | 0
Pre- Modification Recorded Principal Balance | $ 93,000 | $ 0 | $ 93,000 | $ 0
Post- Modification Recorded Principal Balance | $ 93,000 | $ 0 | $ 93,000 | $ 0
Retail Portfolio Segment [Member] |  |  |  |
Number of Contracts | 0 | 7 | 6 | 17
Pre- Modification Recorded Principal Balance | $ 0 | $ 150,000 | $ 531,000 | $ 510,000
Post- Modification Recorded Principal Balance | $ 0 | $ 150,000 | $ 528,000 | $ 510,000
Retail Portfolio Segment [Member] | Home Equity and Other [Member] |  |  |  |
Number of Contracts | 0 | 5 | 4 | 14
Pre- Modification Recorded Principal Balance | $ 0 | $ 82,000 | $ 485,000 | $ 422,000
Post- Modification Recorded Principal Balance | $ 0 | $ 83,000 | $ 482,000 | $ 423,000
Retail Portfolio Segment [Member] | One to Four Family Mortgages [Member] |  |  |  |
Number of Contracts | 0 | 2 | 2 | 3
Pre- Modification Recorded Principal Balance | $ 0 | $ 68,000 | $ 46,000 | $ 88,000
Post- Modification Recorded Principal Balance | $ 0 | $ 67,000 | $ 46,000 | $ 87,000

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=123577603&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=123577603&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=123577603&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: |