Annual report pursuant to Section 13 and 15(d)

SHAREHOLDERS' EQUITY (Details)

v2.4.1.9
SHAREHOLDERS' EQUITY (Details) (USD $)
0 Months Ended 12 Months Ended
Jun. 29, 2011
Jun. 30, 2011
Jun. 07, 2011
Dec. 31, 2014
Category
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2009
Dec. 31, 2008
SHAREHOLDERS' EQUITY [Abstract]                
Number of classification of prompt corrective action regulations       5mcbc_NumberOfCategoriesOfPromptCorrectiveActionRegulations        
Summary of actual capital levels and minimum required levels [Abstract]                
Total capital (to risk weighted assets), actual amount       $ 189,353,000us-gaap_Capital $ 174,433,000us-gaap_Capital      
Total capital (to risk weighted assets), actual ratio (in hundredths)       15.60%us-gaap_CapitalToRiskWeightedAssets 15.70%us-gaap_CapitalToRiskWeightedAssets      
Tier 1 capital (to risk weighted assets), actual amount       174,084,000us-gaap_TierOneRiskBasedCapital 160,455,000us-gaap_TierOneRiskBasedCapital      
Tier 1 capital (to risk weighted assets), actual ratio (in hundredths)       14.30%us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets 14.40%us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets      
Tier 1 capital (to average assets), actual amount       174,084,000us-gaap_TierOneLeverageCapital 160,455,000us-gaap_TierOneLeverageCapital      
Tier 1 capital (to average assets), actual ratio (in hundredths)       11.60%us-gaap_TierOneLeverageCapitalToAverageAssets 10.60%us-gaap_TierOneLeverageCapitalToAverageAssets      
Total capital (to risk weighted assets), minimum required for capital adequacy purposes, amount       97,420,000us-gaap_CapitalRequiredForCapitalAdequacy 88,915,000us-gaap_CapitalRequiredForCapitalAdequacy      
Total capital (to risk weighted assets) minimum required for capital adequacy purposes, ratio (in hundredths)       8.00%us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets 8.00%us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets      
Tier 1 capital (to risk weighted assets), minimum required for capital adequacy purposes, amount       48,706,000us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacy 44,457,000us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacy      
Tier 1 capital (to risk weighted assets), minimum required for capital adequacy purposes, ratio (in hundredths)       4.00%us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets 4.00%us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets      
Tier 1 capital (to average assets), minimum required for capital adequacy purposes, amount       59,998,000us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy 60,482,000us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy      
Tier 1 capital (to average assets), minimum required for capital adequacy purposes, ratio (in hundredths)       4.00%us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets 4.00%us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets      
Trust preferred securities that qualified as Tier one risk based capital       40,000,000mcbc_TierOneRiskBasedCapitalTrustPreferredSecurities        
Convertible Preferred Stock [Abstract]                
Stock issuance costs       102,000us-gaap_PaymentsOfStockIssuanceCosts 0us-gaap_PaymentsOfStockIssuanceCosts 0us-gaap_PaymentsOfStockIssuanceCosts    
Inducement payment       4,700,000mcbc_InducementPayment        
Exchange of preferred stock       0us-gaap_PreferredStockConversionsInducements 17,575,000us-gaap_PreferredStockConversionsInducements 0us-gaap_PreferredStockConversionsInducements    
Subordinated Notes [Abstract]                
Proceeds from issuance of debt       41,238,000us-gaap_ProceedsFromIssuanceOfDebt        
Issuance date       Apr. 21, 2011        
Common Stock [Abstract]                
Number of shares issued from sale of stock (in shares) 4,456,186mcbc_NumberOfSharesIssuedFromSaleOfStock   4,456,186mcbc_NumberOfSharesIssuedFromSaleOfStock          
Average price of common stock shares issued (in dollars per share) $ 2.30us-gaap_SharePrice   $ 2.30us-gaap_SharePrice          
Proceeds from issuance of common stock   20,300,000us-gaap_ProceedsFromIssuanceOfCommonStock   4,000us-gaap_ProceedsFromIssuanceOfCommonStock 0us-gaap_ProceedsFromIssuanceOfCommonStock 0us-gaap_ProceedsFromIssuanceOfCommonStock    
Amount contributed to bank   10,000,000us-gaap_OtherOwnershipInterestsValue            
Warrants [Member]                
Warrant issued [Abstract]                
Warrant issued to purchase common stock (in shares)             1,478,811us-gaap_ClassOfWarrantOrRightOutstanding
/ us-gaap_ClassOfWarrantOrRightAxis
= us-gaap_WarrantMember
 
Exercise price of warrants (in dollars per share)             $ 9.00us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1
/ us-gaap_ClassOfWarrantOrRightAxis
= us-gaap_WarrantMember
 
Fair value of warrants issued             806,000us-gaap_StockAndWarrantsIssuedDuringPeriodValuePreferredStockAndWarrants
/ us-gaap_ClassOfWarrantOrRightAxis
= us-gaap_WarrantMember
 
Warrants per common stock (in dollars per share)             $ 0.54mcbc_WarrantsPerCommonStock
/ us-gaap_ClassOfWarrantOrRightAxis
= us-gaap_WarrantMember
 
Warrant expiration date             Jun. 18, 2015  
Warrants issued during period, expiration period             5 years  
Unsecured Subordinated Debt, Due 2017 [Member]                
Subordinated Notes [Abstract]                
Proceeds from issuance of debt             1,650,000us-gaap_ProceedsFromIssuanceOfDebt
/ us-gaap_DebtInstrumentAxis
= us-gaap_UnsecuredDebtMember
 
Debt instrument due date             Dec. 31, 2017  
Subordinated Note, Due 2018 [Member]                
Subordinated Notes [Abstract]                
Proceeds from issuance of debt       1,000,000us-gaap_ProceedsFromIssuanceOfDebt
/ us-gaap_DebtInstrumentAxis
= us-gaap_SubordinatedDebtMember
       
Debt instrument due date       Dec. 31, 2018        
Series A Preferred Stock [Member]                
Convertible Preferred Stock [Abstract]                
Stock issued in private offerings (in shares)               31,290us-gaap_PreferredStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
Preferred stock coupon rate (in hundredths)               12.00%us-gaap_PreferredStockDividendRatePercentage
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
Preferred stock, liquidation value (in dollars per share)               $ 1,000us-gaap_PreferredStockLiquidationPreference
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
Aggregate liquidation preference               31,300,000us-gaap_PreferredStockLiquidationPreferenceValue
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
Proceeds from issuance of Convertible Preferred Stock               30,600,000us-gaap_ProceedsFromIssuanceOfConvertiblePreferredStock
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
Stock issuance costs               686,000us-gaap_PaymentsOfStockIssuanceCosts
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
Preferred stock, par value (in dollars per share)       $ 0us-gaap_PreferredStockNoParValue
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
       
Amount fixed as denominator for division by liquidation preference (in dollars per share)       $ 5.25mcbc_AmountFixedAsDenominatorForDivisionByLiquidationPreference
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
       
Amount equivalent to cash for each series of preferred stock (in dollars per share)       $ 142mcbc_AmountEquivalentToCashForEachSeriesOfPreferredStock
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
       
Dividend rate for one time cash payments (in hundredths)       5.00%mcbc_DividendRateForOneTimeCashPayments
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
       
Payments from exchange of preferred stock       4,400,000mcbc_PaymentsFromExchangeOfPreferredStock
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
       
Number of shares converted in conversion of Preferred Stock to Common Stock (in shares)       5,973,519us-gaap_ConversionOfStockSharesConverted1
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesAPreferredStockMember
       
Series B Preferred Stock [Member]                
Convertible Preferred Stock [Abstract]                
Stock issued in private offerings (in shares)             2,600us-gaap_PreferredStockSharesIssued
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
 
Preferred stock coupon rate (in hundredths)             9.00%us-gaap_PreferredStockDividendRatePercentage
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
 
Preferred stock, liquidation value (in dollars per share)             $ 1,000us-gaap_PreferredStockLiquidationPreference
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
 
Aggregate liquidation preference             2,600,000us-gaap_PreferredStockLiquidationPreferenceValue
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
 
Proceeds from issuance of Convertible Preferred Stock             2,600,000us-gaap_ProceedsFromIssuanceOfConvertiblePreferredStock
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
 
Stock issuance costs             40,000us-gaap_PaymentsOfStockIssuanceCosts
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
 
Preferred stock, par value (in dollars per share)       $ 0us-gaap_PreferredStockNoParValue
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
       
Amount fixed as denominator for division by liquidation preference (in dollars per share)       $ 5.25mcbc_AmountFixedAsDenominatorForDivisionByLiquidationPreference
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
       
Amount equivalent to cash for each series of preferred stock (in dollars per share)       $ 182mcbc_AmountEquivalentToCashForEachSeriesOfPreferredStock
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
       
Dividend rate for one time cash payments (in hundredths)       4.50%mcbc_DividendRateForOneTimeCashPayments
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
       
Payments from exchange of preferred stock       319,000mcbc_PaymentsFromExchangeOfPreferredStock
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
       
Number of shares exchanged in exchange of Preferred Stock to Common Stock (in shares)       457,519mcbc_ExchangeOfStockSharesExchanged
/ us-gaap_StatementClassOfStockAxis
= us-gaap_SeriesBPreferredStockMember
       
Common Stock [Member]                
Convertible Preferred Stock [Abstract]                
Amount specified by which common stock of shares are divided for cancellation and exchange (in dollars per share)       $ 5.25mcbc_AmountSpecifiedByWhichCommonStockOfSharesAreDividedForCancellationAndExchange
/ us-gaap_StatementEquityComponentsAxis
= us-gaap_CommonClassAMember
       
Bank [Member]                
Summary of actual capital levels and minimum required levels [Abstract]                
Total capital (to risk weighted assets), actual amount       186,276,000us-gaap_Capital
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
171,811,000us-gaap_Capital
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Total capital (to risk weighted assets), actual ratio (in hundredths)       15.30%us-gaap_CapitalToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
15.40%us-gaap_CapitalToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Tier 1 capital (to risk weighted assets), actual amount       170,983,000us-gaap_TierOneRiskBasedCapital
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
157,825,000us-gaap_TierOneRiskBasedCapital
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Tier 1 capital (to risk weighted assets), actual ratio (in hundredths)       14.00%us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
14.20%us-gaap_TierOneRiskBasedCapitalToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Tier 1 capital (to average assets), actual amount       170,983,000us-gaap_TierOneLeverageCapital
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
157,825,000us-gaap_TierOneLeverageCapital
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Tier 1 capital (to average assets), actual ratio (in hundredths)       11.40%us-gaap_TierOneLeverageCapitalToAverageAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
10.50%us-gaap_TierOneLeverageCapitalToAverageAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Total capital (to risk weighted assets), minimum required for capital adequacy purposes, amount       97,575,000us-gaap_CapitalRequiredForCapitalAdequacy
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
88,968,000us-gaap_CapitalRequiredForCapitalAdequacy
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Total capital (to risk weighted assets) minimum required for capital adequacy purposes, ratio (in hundredths)       8.00%us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
8.00%us-gaap_CapitalRequiredForCapitalAdequacyToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Tier 1 capital (to risk weighted assets), minimum required for capital adequacy purposes, amount       48,788,000us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacy
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
44,484,000us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacy
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Tier 1 capital (to risk weighted assets), minimum required for capital adequacy purposes, ratio (in hundredths)       4.00%us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
4.00%us-gaap_TierOneRiskBasedCapitalRequiredForCapitalAdequacyToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Tier 1 capital (to average assets), minimum required for capital adequacy purposes, amount       59,923,000us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
60,407,000us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacy
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Tier 1 capital (to average assets), minimum required for capital adequacy purposes, ratio (in hundredths)       4.00%us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
4.00%us-gaap_TierOneLeverageCapitalRequiredForCapitalAdequacyToAverageAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Total capital (to risk weighted assets) to be well capitalized under prompt corrective action regulations, amount       121,969,000us-gaap_CapitalRequiredToBeWellCapitalized
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
111,210,000us-gaap_CapitalRequiredToBeWellCapitalized
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Total capital (to risk weighted assets) to be well capitalized under prompt corrective action regulations, ratio (in hundredths)       10.00%us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
10.00%us-gaap_CapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Tier 1 capital (to risk weighted assets) to be well capitalized under prompt corrective action regulations, amount       73,182,000us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
66,726,000us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalized
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Tier 1 capital (to risk weighted assets) to be well capitalized under prompt corrective action regulations, ratio (in hundredths)       6.00%us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
6.00%us-gaap_TierOneRiskBasedCapitalRequiredToBeWellCapitalizedToRiskWeightedAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Tier 1 capital (to average assets) to be well capitalized under prompt corrective action regulations, amount       74,904,000us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
75,509,000us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalized
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Tier 1 capital (to average assets) to be well capitalized under prompt corrective action regulations, ratio (in hundredths)       5.00%us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
5.00%us-gaap_TierOneLeverageCapitalRequiredToBeWellCapitalizedToAverageAssets
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember
     
Trust preferred securities that qualified as Tier one risk based capital         $ 40,000,000mcbc_TierOneRiskBasedCapitalTrustPreferredSecurities
/ dei_LegalEntityAxis
= us-gaap_SubsidiariesMember