Annual report pursuant to Section 13 and 15(d)

LOANS, Credit Quality Indicators (Details)

v2.4.1.9
LOANS, Credit Quality Indicators (Details) (USD $)
In Thousands, unless otherwise specified
 12 Months Ended
Dec. 31, 2014
Grading
Dec. 31, 2013
Risk grade category of commercial loans by class of loans [Abstract]    
Number point grading system used for loan quality 8mcbc_NumberPointGradingSystemUsedForLoanQuality  
Internal ratings of loans considered substandard, or worse 6 or worse  
Loans classified as substandard or worse [Abstract]    
Loans classified as substandard or worse $ 16,304us-gaap_LongTermAccountsNotesAndLoansReceivableNetNoncurrent $ 27,652us-gaap_LongTermAccountsNotesAndLoansReceivableNetNoncurrent
Not Classified as Impaired [Member]    
Loans classified as substandard or worse [Abstract]    
Loans classified as substandard or worse 4,220us-gaap_LongTermAccountsNotesAndLoansReceivableNetNoncurrent
/ mcbc_FinancingReceivableInformationByClassificationAxis
= mcbc_NotClassifiedAsImpairedMember 		7,400us-gaap_LongTermAccountsNotesAndLoansReceivableNetNoncurrent
/ mcbc_FinancingReceivableInformationByClassificationAxis
= mcbc_NotClassifiedAsImpairedMember
Classified as Impaired [Member]    
Loans classified as substandard or worse [Abstract]    
Loans classified as substandard or worse 12,084us-gaap_LongTermAccountsNotesAndLoansReceivableNetNoncurrent
/ mcbc_FinancingReceivableInformationByClassificationAxis
= mcbc_ClassifiedAsImpairedMember 		20,252us-gaap_LongTermAccountsNotesAndLoansReceivableNetNoncurrent
/ mcbc_FinancingReceivableInformationByClassificationAxis
= mcbc_ClassifiedAsImpairedMember
Excellent [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 343us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember 		509us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember
Above Average [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 17,180us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember 		23,638us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember
Good Quality [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 238,208us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember 		179,865us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember
Acceptable Risk [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 494,080us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		444,001us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember
Marginally Acceptable [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 52,090us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		70,774us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember
Substandard [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 8,793us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		16,474us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember
Doubtful [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 7,511us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember 		11,178us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember
Loss [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember 		0us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember
Commercial and Industrial [Member] | Excellent [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 343us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember 		509us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember
Commercial and Industrial [Member] | Above Average [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 11,177us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember 		15,836us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember
Commercial and Industrial [Member] | Good Quality [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 118,382us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember 		81,577us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember
Commercial and Industrial [Member] | Acceptable Risk [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 182,651us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		155,680us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember
Commercial and Industrial [Member] | Marginally Acceptable [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 8,448us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		13,513us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember
Commercial and Industrial [Member] | Substandard [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 1,068us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		1,359us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember
Commercial and Industrial [Member] | Doubtful [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 5,605us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember 		5,625us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember
Commercial and Industrial [Member] | Loss [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember
Residential Developed [Member] | Excellent [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialRealEstateMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialRealEstateMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember
Residential Developed [Member] | Above Average [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialRealEstateMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialRealEstateMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember
Residential Developed [Member] | Good Quality [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 2,491us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialRealEstateMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember 		2,039us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialRealEstateMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember
Residential Developed [Member] | Acceptable Risk [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 4,702us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialRealEstateMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		5,653us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialRealEstateMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember
Residential Developed [Member] | Marginally Acceptable [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 4,491us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialRealEstateMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		5,232us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialRealEstateMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember
Residential Developed [Member] | Substandard [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 842us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialRealEstateMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		2,616us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialRealEstateMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember
Residential Developed [Member] | Doubtful [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 245us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialRealEstateMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember 		2,590us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialRealEstateMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember
Residential Developed [Member] | Loss [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialRealEstateMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialRealEstateMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember
Unsecured to Residential Developers [Member] | Excellent [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember
Unsecured to Residential Developers [Member] | Above Average [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember
Unsecured to Residential Developers [Member] | Good Quality [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember
Unsecured to Residential Developers [Member] | Acceptable Risk [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 7,496us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		7,309us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember
Unsecured to Residential Developers [Member] | Marginally Acceptable [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		6us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember
Unsecured to Residential Developers [Member] | Substandard [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember
Unsecured to Residential Developers [Member] | Doubtful [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember
Unsecured to Residential Developers [Member] | Loss [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember
Vacant and Unimproved [Member] | Excellent [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember
Vacant and Unimproved [Member] | Above Average [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember
Vacant and Unimproved [Member] | Good Quality [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 12,105us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember 		11,191us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember
Vacant and Unimproved [Member] | Acceptable Risk [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 30,997us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		24,638us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember
Vacant and Unimproved [Member] | Marginally Acceptable [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 7,241us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		6,761us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember
Vacant and Unimproved [Member] | Substandard [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 29us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		398us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember
Vacant and Unimproved [Member] | Doubtful [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember
Vacant and Unimproved [Member] | Loss [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember
Commercial Development [Member] | Excellent [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember
Commercial Development [Member] | Above Average [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember
Commercial Development [Member] | Good Quality [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember
Commercial Development [Member] | Acceptable Risk [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 3,643us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		1,673us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember
Commercial Development [Member] | Marginally Acceptable [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 211us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		532us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember
Commercial Development [Member] | Substandard [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 199us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		207us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember
Commercial Development [Member] | Doubtful [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 29us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember 		23us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember
Commercial Development [Member] | Loss [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember
Residential Improved [Member] | Excellent [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember
Residential Improved [Member] | Above Average [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 103us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember 		109us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember
Residential Improved [Member] | Good Quality [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 16,291us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember 		15,121us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember
Residential Improved [Member] | Acceptable Risk [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 43,928us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		45,018us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember
Residential Improved [Member] | Marginally Acceptable [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 6,428us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		9,391us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember
Residential Improved [Member] | Substandard [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 2,096us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		6,226us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember
Residential Improved [Member] | Doubtful [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 766us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember 		429us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember
Residential Improved [Member] | Loss [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember
Commercial Improved [Member] | Excellent [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember
Commercial Improved [Member] | Above Average [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 4,392us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember 		7,382us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember
Commercial Improved [Member] | Good Quality [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 61,543us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember 		45,391us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember
Commercial Improved [Member] | Acceptable Risk [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 178,169us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		161,897us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember
Commercial Improved [Member] | Marginally Acceptable [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 20,558us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		24,937us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember
Commercial Improved [Member] | Substandard [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 4,229us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		5,075us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember
Commercial Improved [Member] | Doubtful [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 866us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember 		2,511us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember
Commercial Improved [Member] | Loss [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember
Manufacturing and Industrial [Member] | Excellent [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember
Manufacturing and Industrial [Member] | Above Average [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 1,508us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember 		311us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember
Manufacturing and Industrial [Member] | Good Quality [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 27,396us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember 		24,546us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember
Manufacturing and Industrial [Member] | Acceptable Risk [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 42,494us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		42,133us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember
Manufacturing and Industrial [Member] | Marginally Acceptable [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 4,713us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		10,402us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember
Manufacturing and Industrial [Member] | Substandard [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 330us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		593us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember
Manufacturing and Industrial [Member] | Doubtful [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember
Manufacturing and Industrial [Member] | Loss [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember
Residential Mortgage [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 190,249us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialMortgageMember 		188,648us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialMortgageMember
Residential Mortgage [Member] | Performing [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 189,946us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ mcbc_FinancingReceivableInformationByPaymentActivityAxis
= us-gaap_PerformingFinancingReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialMortgageMember 		188,648us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ mcbc_FinancingReceivableInformationByPaymentActivityAxis
= us-gaap_PerformingFinancingReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialMortgageMember
Residential Mortgage [Member] | Nonperforming [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 303us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ mcbc_FinancingReceivableInformationByPaymentActivityAxis
= us-gaap_NonperformingFinancingReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialMortgageMember 		0us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ mcbc_FinancingReceivableInformationByPaymentActivityAxis
= us-gaap_NonperformingFinancingReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialMortgageMember
Unsecured [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 948us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_UnsecuredDebtMember 		1,337us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_UnsecuredDebtMember
Unsecured [Member] | Performing [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 930us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ mcbc_FinancingReceivableInformationByPaymentActivityAxis
= us-gaap_PerformingFinancingReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_UnsecuredDebtMember 		1,337us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ mcbc_FinancingReceivableInformationByPaymentActivityAxis
= us-gaap_PerformingFinancingReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_UnsecuredDebtMember
Unsecured [Member] | Nonperforming [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 18us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ mcbc_FinancingReceivableInformationByPaymentActivityAxis
= us-gaap_NonperformingFinancingReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_UnsecuredDebtMember 		0us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ mcbc_FinancingReceivableInformationByPaymentActivityAxis
= us-gaap_NonperformingFinancingReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_UnsecuredDebtMember
Home Equity [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 98,887us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember 		95,961us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember
Home Equity [Member] | Performing [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 98,465us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ mcbc_FinancingReceivableInformationByPaymentActivityAxis
= us-gaap_PerformingFinancingReceivableMember
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember 		95,961us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ mcbc_FinancingReceivableInformationByPaymentActivityAxis
= us-gaap_PerformingFinancingReceivableMember
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