Annual report pursuant to Section 13 and 15(d)

EMPLOYEE BENEFITS (Details)

v2.4.1.9
EMPLOYEE BENEFITS (Details) (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
EMPLOYEE BENEFITS [Abstract]      
Employer matching contribution, first (in hundredths) 100.00%us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent    
Employee contribution, first (in hundredths) 3.00%mcbc_EmployeeContributionAtThresholdI    
Employer matching contribution, second (in hundredths) 50.00%mcbc_EmployerContributionAtThresholdIi    
Employee contribution, second (in hundredths) 3.00%mcbc_EmployeeContributionAtThresholdIi    
Maximum employer matching contribution (in hundredths) 5.00%mcbc_MaximumEmployerMatchingContribution    
Number of shares permitted under the plan (in shares) 210,000us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized    
Employer contributions $ 630,000us-gaap_DeferredCompensationArrangementWithIndividualEmployerContribution $ 584,000us-gaap_DeferredCompensationArrangementWithIndividualEmployerContribution $ 0us-gaap_DeferredCompensationArrangementWithIndividualEmployerContribution