XML 60 R50.htm IDEA: XBRL DOCUMENT v3.25.2

Note 3 - Loans and Allowance for Credit Losses - Financial Effect by Type of Modification (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2024
Contractual Interest Rate Reduction [Member]
Modified in period	$ 0	$ 0	$ 0
Contractual Interest Rate Reduction [Member] | Commercial Portfolio Segment [Member]
Modified in period	0	0	0
Contractual Interest Rate Reduction [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Modified in period	0	0	0
Contractual Interest Rate Reduction [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Modified in period	0	0	0
Contractual Interest Rate Reduction [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Modified in period	0	0	0
Contractual Interest Rate Reduction [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Modified in period	0	0	0
Contractual Interest Rate Reduction [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Modified in period	0	0	0
Contractual Interest Rate Reduction [Member] | Retail Portfolio Segment [Member]
Modified in period	0	0	0
Contractual Interest Rate Reduction [Member] | Retail Portfolio Segment [Member] | Loans Categorized as 1-4 Family Mortgages [Member]
Modified in period	0	0	0
Contractual Interest Rate Reduction [Member] | Retail Portfolio Segment [Member] | Other Consumer Loans [Member]
Modified in period	0	0	0
Extended Maturity [Member]
Modified in period	20	1,818	2,318
Extended Maturity [Member] | Commercial Portfolio Segment [Member]
Modified in period	20	1,818	2,318
Extended Maturity [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Modified in period	20	1,818	2,318
Extended Maturity [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Modified in period	0	0	0
Extended Maturity [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Modified in period	0	0	0
Extended Maturity [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Modified in period	0	0	0
Extended Maturity [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Modified in period	0	0	0
Extended Maturity [Member] | Retail Portfolio Segment [Member]
Modified in period	0	0	0
Extended Maturity [Member] | Retail Portfolio Segment [Member] | Loans Categorized as 1-4 Family Mortgages [Member]
Modified in period	0	0	0
Extended Maturity [Member] | Retail Portfolio Segment [Member] | Other Consumer Loans [Member]
Modified in period	0	0	0
Principal Forgiveness [Member]
Modified in period	0	0	0
Principal Forgiveness [Member] | Commercial Portfolio Segment [Member]
Modified in period	0	0	0
Principal Forgiveness [Member] | Commercial Portfolio Segment [Member] | Commercial and Industrial [Member]
Modified in period	0	0	0
Principal Forgiveness [Member] | Commercial Portfolio Segment [Member] | Vacant Land and Land Development and Residential Construction Loan [Member]
Modified in period	0	0	0
Principal Forgiveness [Member] | Commercial Portfolio Segment [Member] | Real Estate Owner Occupied Loan [Member]
Modified in period	0	0	0
Principal Forgiveness [Member] | Commercial Portfolio Segment [Member] | Real Estate Non Owner Occupied Loan [Member]
Modified in period	0	0	0
Principal Forgiveness [Member] | Commercial Portfolio Segment [Member] | Real Estate Multi Family and Residential Rental Loan [Member]
Modified in period	0	0	0
Principal Forgiveness [Member] | Retail Portfolio Segment [Member]
Modified in period	0	0	0
Principal Forgiveness [Member] | Retail Portfolio Segment [Member] | Loans Categorized as 1-4 Family Mortgages [Member]
Modified in period	0	0	0
Principal Forgiveness [Member] | Retail Portfolio Segment [Member] | Other Consumer Loans [Member]
Modified in period	$ 0	$ 0	$ 0

X

- Definition

Amortized cost of financing receivable modified during period for debtor experiencing financial difficulty.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 12A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481933/310-10-55-12A

Reference 2: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 33
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-33

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 310
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481962/310-10-50-42

+ Details

Name:	us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_ContractualInterestRateReductionMember
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_LoansCategorizedAs14FamilyMortgagesMember
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_LoanRestructuringModificationAxis=us-gaap_ExtendedMaturityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_LoanRestructuringModificationAxis=us-gaap_PrincipalForgivenessMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: