Quarterly report pursuant to Section 13 or 15(d)

FAIR VALUE (Details)

v2.4.1.9
FAIR VALUE (Details) (USD $)
In Thousands, unless otherwise specified
3 Months Ended 12 Months Ended
Mar. 31, 2015
Dec. 31, 2014
FAIR VALUE [Abstract]    
Number of levels of input 3mcbc_NumberOfLevels  
Impaired Loans [Member] | Sales Comparison Approach [Member]    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Asset (liability) fair value 10,780us-gaap_AssetsFairValueDisclosure
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Impaired Loans [Member] | Sales Comparison Approach [Member] | Minimum [Member]    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Adjustment for differences between comparable sales (in hundredths) 1.00%us-gaap_FairValueInputsComparabilityAdjustments
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Impaired Loans [Member] | Sales Comparison Approach [Member] | Maximum [Member]    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Adjustment for differences between comparable sales (in hundredths) 20.00%us-gaap_FairValueInputsComparabilityAdjustments
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20.00%us-gaap_FairValueInputsComparabilityAdjustments
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Impaired Loans [Member] | Income Approach [Member] | Minimum [Member]    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Capitalization rate (in hundredths) 9.50%us-gaap_FairValueInputsCapRate
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Impaired Loans [Member] | Income Approach [Member] | Maximum [Member]    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Capitalization rate (in hundredths) 11.00%us-gaap_FairValueInputsCapRate
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Other Real Estate Owned [Member] | Sales Comparison Approach [Member]    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Asset (liability) fair value 23,291us-gaap_AssetsFairValueDisclosure
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Other Real Estate Owned [Member] | Sales Comparison Approach [Member] | Minimum [Member]    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Adjustment for differences between comparable sales (in hundredths) 4.50%us-gaap_FairValueInputsComparabilityAdjustments
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Other Real Estate Owned [Member] | Sales Comparison Approach [Member] | Maximum [Member]    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Adjustment for differences between comparable sales (in hundredths) 22.00%us-gaap_FairValueInputsComparabilityAdjustments
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Other Real Estate Owned [Member] | Income Approach [Member] | Minimum [Member]    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Capitalization rate (in hundredths) 9.50%us-gaap_FairValueInputsCapRate
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Other Real Estate Owned [Member] | Income Approach [Member] | Maximum [Member]    
Fair Value Inputs, Assets, Quantitative Information [Line Items]    
Capitalization rate (in hundredths) 11.00%us-gaap_FairValueInputsCapRate
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Recurring Basis [Member]    
Asset measured at fair value on recurring basis [Abstract]    
U.S. Treasury and federal agency securities 65,700mcbc_UnitedStatesGovernmentTreasuryAndFederalAgencySecuritiesFairValueDisclosure
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67,164mcbc_UnitedStatesGovernmentTreasuryAndFederalAgencySecuritiesFairValueDisclosure
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U.S. Agency MBS and CMOs 15,932mcbc_USAgencyMbsAndCmosFairValueDisclosure
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16,688mcbc_USAgencyMbsAndCmosFairValueDisclosure
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Tax-exempt state and municipal bonds 36,227mcbc_StateAndMunicipalBondsFairValueDisclosure
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37,461mcbc_StateAndMunicipalBondsFairValueDisclosure
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Taxable state and municipal bonds 23,960mcbc_TaxableStateAndMunicipalBondsFairValueDisclosure
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25,293mcbc_TaxableStateAndMunicipalBondsFairValueDisclosure
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Corporate bonds and other debt securities 12,305mcbc_CorporateBondsAndOtherDebtSecuritiesFairValueDisclosure
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13,766mcbc_CorporateBondsAndOtherDebtSecuritiesFairValueDisclosure
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Other equity securities 1,516us-gaap_EquityMethodInvestmentsFairValueDisclosure
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1,502us-gaap_EquityMethodInvestmentsFairValueDisclosure
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Loans held for sale 2,368us-gaap_LoansHeldForSaleFairValueDisclosure
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2,347us-gaap_LoansHeldForSaleFairValueDisclosure
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Interest rate swaps 224us-gaap_InterestRateDerivativeAssetsAtFairValue
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140us-gaap_InterestRateDerivativeAssetsAtFairValue
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Interest rate swaps (224)us-gaap_InterestRateDerivativeLiabilitiesAtFairValue
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(140)us-gaap_InterestRateDerivativeLiabilitiesAtFairValue
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Recurring Basis [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]    
Asset measured at fair value on recurring basis [Abstract]    
U.S. Treasury and federal agency securities 0mcbc_UnitedStatesGovernmentTreasuryAndFederalAgencySecuritiesFairValueDisclosure
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Asset measured at fair value on recurring basis [Abstract]    
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U.S. Agency MBS and CMOs 15,932mcbc_USAgencyMbsAndCmosFairValueDisclosure
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Nonrecurring Basis [Member]    
Asset measured at fair value on non-recurring basis [Abstract]    
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Asset measured at fair value on non-recurring basis [Abstract]    
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Asset measured at fair value on non-recurring basis [Abstract]    
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Asset measured at fair value on non-recurring basis [Abstract]    
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