Annual report pursuant to Section 13 and 15(d)

RELATED PARTY TRANSACTIONS (Details)

v2.4.1.9
RELATED PARTY TRANSACTIONS (Details) (USD $)
 12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Loans to principal officers, directors, and their affiliates [Roll Forward]    
Beginning balance $ 3,462,000us-gaap_LoansAndLeasesReceivableRelatedParties $ 5,645,000us-gaap_LoansAndLeasesReceivableRelatedParties
New loans and renewals 21,594,000us-gaap_LoansAndLeasesReceivableRelatedPartiesAdditions 10,704,000us-gaap_LoansAndLeasesReceivableRelatedPartiesAdditions
Repayments and renewals (14,979,000)us-gaap_LoansAndLeasesReceivableRelatedPartiesCollections (12,887,000)us-gaap_LoansAndLeasesReceivableRelatedPartiesCollections
Effect of changes in related parties 0mcbc_LoansAndLeasesReceivableEffectOfChangesInRelatedParties 0mcbc_LoansAndLeasesReceivableEffectOfChangesInRelatedParties
Ending balance 10,077,000us-gaap_LoansAndLeasesReceivableRelatedParties 3,462,000us-gaap_LoansAndLeasesReceivableRelatedParties
Principal Officers, Directors, and Affiliates [Member]    
Loans to principal officers, directors, and their affiliates [Roll Forward]    
Deposits from principal officers, directors, and their affiliates $ 80,300,000us-gaap_RelatedPartyDepositLiabilities
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= mcbc_PrincipalOfficersDirectorsAndTheirAffiliatesMember 		$ 113,800,000us-gaap_RelatedPartyDepositLiabilities
/ us-gaap_RelatedPartyTransactionsByRelatedPartyAxis
= mcbc_PrincipalOfficersDirectorsAndTheirAffiliatesMember