Quarterly report pursuant to Section 13 or 15(d)

LOANS, Credit Quality Indicators (Details)

v2.4.1.9
LOANS, Credit Quality Indicators (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
Grading
Dec. 31, 2014
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  
Excellent [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 317us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember 		$ 343us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember
Above Average [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 15,757us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember 		17,180us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember
Good Quality [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 249,452us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember 		238,208us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember
Acceptable Risk [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 496,634us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		494,080us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember
Marginally Acceptable [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 51,123us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		52,090us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember
Substandard [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 7,002us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		8,793us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember
Doubtful [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 9,317us-gaap_NotesReceivableNet
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember 		7,511us-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 317us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember 		343us-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 9,822us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember 		11,177us-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 122,058us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember 		118,382us-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 192,125us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		182,651us-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 9,431us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		8,448us-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 1,045us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		1,068us-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 6,732us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_CommercialRealEstateConstructionFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember 		5,605us-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
= mcbc_CommercialRealEstateResidentialDevelopedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_ExcellentMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialDevelopedFinancingReceivableMember
/ 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
= mcbc_CommercialRealEstateResidentialDevelopedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialDevelopedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember
Residential Developed [Member] | Good Quality [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 2,713us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialDevelopedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember 		2,491us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialDevelopedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember
Residential Developed [Member] | Acceptable Risk [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 4,390us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialDevelopedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		4,702us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialDevelopedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember
Residential Developed [Member] | Marginally Acceptable [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 4,016us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialDevelopedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		4,491us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialDevelopedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember
Residential Developed [Member] | Substandard [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 811us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialDevelopedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		842us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialDevelopedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember
Residential Developed [Member] | Doubtful [Member]    
Risk grade category of commercial loans by class of loans [Abstract]    
Total loans 213us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialDevelopedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember 		245us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialDevelopedFinancingReceivableMember
/ 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
= mcbc_CommercialRealEstateResidentialDevelopedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_UnlikelyToBeCollectedFinancingReceivableMember 		0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialDevelopedFinancingReceivableMember
/ 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 7,220us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateUnsecuredToResidentialDevelopersReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		7,496us-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 		0us-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 21,971us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember 		12,105us-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 21,312us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		30,997us-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 6,821us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		7,241us-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 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateVacantAndUnimprovedReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		29us-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 1,281us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		3,643us-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 205us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		211us-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 197us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		199us-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 49us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialDevelopmentFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember 		29us-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 0us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember 		103us-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 16,993us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember 		16,291us-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 42,898us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		43,928us-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 5,850us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		6,428us-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 2,021us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		2,096us-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 604us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateResidentialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember 		766us-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 4,705us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember 		4,392us-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 58,863us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember 		61,543us-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 185,384us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		178,169us-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 20,526us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		20,558us-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 2,603us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		4,229us-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 1,719us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateCommercialImprovedFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_DoubtfulMember 		866us-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 1,230us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AboveAverageMember 		1,508us-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 26,854us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_GoodQualityMember 		27,396us-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 42,024us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_AcceptableRiskMember 		42,494us-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 4,274us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_MarginallyAcceptableMember 		4,713us-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 325us-gaap_NotesReceivableNet
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialRealEstateManufacturingAndIndustrialFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_SubstandardMember 		330us-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
Commercial Loans [Member] | Substandard or Worse [Member]    
Loans classified as substandard or worse [Abstract]    
Not classified as impaired 3,056mcbc_LoansAndLeasesReceivableNonperformingNotClassifiedAsImpaired
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_SubstandardOrWorseMember 		4,220mcbc_LoansAndLeasesReceivableNonperformingNotClassifiedAsImpaired
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_SubstandardOrWorseMember
Classified as impaired 13,263mcbc_LoansAndLeasesReceivableNonperformingClassifiedAsImpaired
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_SubstandardOrWorseMember 		12,084mcbc_LoansAndLeasesReceivableNonperformingClassifiedAsImpaired
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_SubstandardOrWorseMember
Loans classified as substandard or worse 16,319us-gaap_LongTermAccountsNotesAndLoansReceivableNetNoncurrent
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_SubstandardOrWorseMember 		16,304us-gaap_LongTermAccountsNotesAndLoansReceivableNetNoncurrent
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_CommercialSegmentMember
/ us-gaap_InternalCreditAssessmentAxis
= mcbc_SubstandardOrWorseMember
Residential Mortgage [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 199,042us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialMortgageMember 		190,249us-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 198,980us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialMortgageMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_PerformingFinancingReceivableMember 		189,946us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialMortgageMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_PerformingFinancingReceivableMember
Residential Mortgage [Member] | Nonperforming [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 62us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialMortgageMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_NonperformingFinancingReceivableMember 		303us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ResidentialMortgageMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_NonperformingFinancingReceivableMember
Unsecured [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 821us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_ConsumerUnsecuredFinancingReceivableMember 		948us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_ConsumerUnsecuredFinancingReceivableMember
Unsecured [Member] | Performing [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 821us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_ConsumerUnsecuredFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_PerformingFinancingReceivableMember 		930us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_ConsumerUnsecuredFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_PerformingFinancingReceivableMember
Unsecured [Member] | Nonperforming [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 0us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_ConsumerUnsecuredFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_NonperformingFinancingReceivableMember 		18us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= mcbc_ConsumerUnsecuredFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_NonperformingFinancingReceivableMember
Home Equity [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 95,770us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_HomeEquityMember 		98,887us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
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= us-gaap_HomeEquityMember
Home Equity [Member] | Performing [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 95,414us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
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/ us-gaap_InternalCreditAssessmentAxis
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/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_PerformingFinancingReceivableMember
Home Equity [Member] | Nonperforming [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 356us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
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/ us-gaap_InternalCreditAssessmentAxis
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/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_NonperformingFinancingReceivableMember
Other Secured [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 10,076us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
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/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerOtherFinancingReceivableMember
Other Secured [Member] | Performing [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 10,076us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
/ us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis
= us-gaap_ConsumerOtherFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_PerformingFinancingReceivableMember 		10,194us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
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= us-gaap_ConsumerOtherFinancingReceivableMember
/ us-gaap_InternalCreditAssessmentAxis
= us-gaap_PerformingFinancingReceivableMember
Other Secured [Member] | Nonperforming [Member]    
Recorded investment in consumer loans based on payment activity [Abstract]    
Recorded investment in consumer loans 0us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
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= us-gaap_NonperformingFinancingReceivableMember 		$ 0us-gaap_LoansAndLeasesReceivableConsumerNetOfDeferredIncome
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/ us-gaap_InternalCreditAssessmentAxis
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