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Fair Value Disclosures Part 1 (Details) (USD $)
Mar. 31, 2015
Dec. 31, 2014
Fair Value Disclosures [Abstract]    
Value of collateral-dependent impaired loans that will be reviewed by independent third party, minimum $ 250,000ibcp_ValueOfCollateralDependentImpairedLoansThatWillBeReviewedByIndependentThirdPartyMinimum  
Value of collateral-dependent impaired loans that will be reviewed by special assets group, maximum 250,000ibcp_ValueOfCollateralDependentImpairedLoansThatWillBeReviewedBySpecialAssetsGroupMaximum  
Assets [Abstract]    
Trading securities 213,000us-gaap_TradingSecurities 203,000us-gaap_TradingSecurities
Securities available for sale 571,762,000us-gaap_AvailableForSaleSecurities 533,178,000us-gaap_AvailableForSaleSecurities
ASSETS [Abstract]    
Capitalized mortgage loan servicing rights 8,129,000ibcp_CapitalizedMortgageLoanServicingRightsFairValueDisclosure 9,197,000ibcp_CapitalizedMortgageLoanServicingRightsFairValueDisclosure
U.S. Agency [Member]    
Assets [Abstract]    
Securities available for sale 35,529,000us-gaap_AvailableForSaleSecurities
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= us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember
35,006,000us-gaap_AvailableForSaleSecurities
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= us-gaap_USGovernmentCorporationsAndAgenciesSecuritiesMember
U.S. Agency Residential Mortgage-Backed [Member]    
Assets [Abstract]    
Securities available for sale 234,254,000us-gaap_AvailableForSaleSecurities
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257,558,000us-gaap_AvailableForSaleSecurities
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= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
U.S. Agency Commercial Mortgage-Backed [Member]    
Assets [Abstract]    
Securities available for sale 33,081,000us-gaap_AvailableForSaleSecurities
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33,728,000us-gaap_AvailableForSaleSecurities
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= us-gaap_CommercialMortgageBackedSecuritiesMember
Private Label Residential Mortgage-Backed [Member]    
Assets [Abstract]    
Securities available for sale 5,820,000us-gaap_AvailableForSaleSecurities
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6,013,000us-gaap_AvailableForSaleSecurities
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= us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Other Asset Backed [Member]    
Assets [Abstract]    
Securities available for sale 95,191,000us-gaap_AvailableForSaleSecurities
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32,353,000us-gaap_AvailableForSaleSecurities
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= us-gaap_AssetBackedSecuritiesMember
Obligations of States and Political Subdivisions [Member]    
Assets [Abstract]    
Securities available for sale 142,788,000us-gaap_AvailableForSaleSecurities
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= us-gaap_USStatesAndPoliticalSubdivisionsMember
143,415,000us-gaap_AvailableForSaleSecurities
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= us-gaap_USStatesAndPoliticalSubdivisionsMember
Corporate [Member]    
Assets [Abstract]    
Securities available for sale 22,661,000us-gaap_AvailableForSaleSecurities
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= us-gaap_CorporateDebtSecuritiesMember
22,664,000us-gaap_AvailableForSaleSecurities
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= us-gaap_CorporateDebtSecuritiesMember
Trust Preferred [Member]    
Assets [Abstract]    
Securities available for sale 2,438,000us-gaap_AvailableForSaleSecurities
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= us-gaap_TrustPreferredSecuritiesSubjectToMandatoryRedemptionMember
2,441,000us-gaap_AvailableForSaleSecurities
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= us-gaap_TrustPreferredSecuritiesSubjectToMandatoryRedemptionMember
Fair Value Measurements [Member] | Fair Value, Measurements, Recurring [Member]    
Assets [Abstract]    
Trading securities 213,000us-gaap_TradingSecurities
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203,000us-gaap_TradingSecurities
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Loans held for sale 30,932,000us-gaap_LoansHeldForSaleFairValueDisclosure
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23,662,000us-gaap_LoansHeldForSaleFairValueDisclosure
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Derivatives 1,268,000us-gaap_DerivativeAssets
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[1] 619,000us-gaap_DerivativeAssets
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[1]
Liabilities [Abstract]    
Derivatives 666,000us-gaap_DerivativeLiabilities
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[2] 366,000us-gaap_DerivativeLiabilities
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[2]
Fair Value Measurements [Member] | Fair Value, Measurements, Recurring [Member] | U.S. Agency [Member]    
Assets [Abstract]    
Securities available for sale 35,529,000us-gaap_AvailableForSaleSecurities
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35,006,000us-gaap_AvailableForSaleSecurities
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Fair Value Measurements [Member] | Fair Value, Measurements, Recurring [Member] | U.S. Agency Residential Mortgage-Backed [Member]    
Assets [Abstract]    
Securities available for sale 234,254,000us-gaap_AvailableForSaleSecurities
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257,558,000us-gaap_AvailableForSaleSecurities
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Fair Value Measurements [Member] | Fair Value, Measurements, Recurring [Member] | U.S. Agency Commercial Mortgage-Backed [Member]    
Assets [Abstract]    
Securities available for sale 33,081,000us-gaap_AvailableForSaleSecurities
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33,728,000us-gaap_AvailableForSaleSecurities
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Fair Value Measurements [Member] | Fair Value, Measurements, Recurring [Member] | Private Label Residential Mortgage-Backed [Member]    
Assets [Abstract]    
Securities available for sale 5,820,000us-gaap_AvailableForSaleSecurities
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6,013,000us-gaap_AvailableForSaleSecurities
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Fair Value Measurements [Member] | Fair Value, Measurements, Recurring [Member] | Other Asset Backed [Member]    
Assets [Abstract]    
Securities available for sale 95,191,000us-gaap_AvailableForSaleSecurities
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32,353,000us-gaap_AvailableForSaleSecurities
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Fair Value Measurements [Member] | Fair Value, Measurements, Recurring [Member] | Obligations of States and Political Subdivisions [Member]    
Assets [Abstract]    
Securities available for sale 142,788,000us-gaap_AvailableForSaleSecurities
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143,415,000us-gaap_AvailableForSaleSecurities
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Fair Value Measurements [Member] | Fair Value, Measurements, Recurring [Member] | Corporate [Member]    
Assets [Abstract]    
Securities available for sale 22,661,000us-gaap_AvailableForSaleSecurities
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22,664,000us-gaap_AvailableForSaleSecurities
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Fair Value Measurements [Member] | Fair Value, Measurements, Recurring [Member] | Trust Preferred [Member]    
Assets [Abstract]    
Securities available for sale 2,438,000us-gaap_AvailableForSaleSecurities
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2,441,000us-gaap_AvailableForSaleSecurities
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Fair Value Measurements [Member] | Fair Value, Measurements, Nonrecurring [Member]    
ASSETS [Abstract]    
Capitalized mortgage loan servicing rights 8,129,000ibcp_CapitalizedMortgageLoanServicingRightsFairValueDisclosure
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[3] 9,197,000ibcp_CapitalizedMortgageLoanServicingRightsFairValueDisclosure
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[3]
Fair Value Measurements [Member] | Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member]    
Commercial [Abstract]    
Income producing - real estate 786,000ibcp_IncomeProducingRealEstateFairValueDisclosure
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[4] 869,000ibcp_IncomeProducingRealEstateFairValueDisclosure
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[4]
Land, land development & construction - real estate 142,000ibcp_LandLandDevelopmentAndConstructionRealEstateFairValueDisclosure
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[4] 354,000ibcp_LandLandDevelopmentAndConstructionRealEstateFairValueDisclosure
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[4]
Commercial and industrial 2,511,000us-gaap_LoansReceivableCommercialAndIndustrial
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[4] 2,601,000us-gaap_LoansReceivableCommercialAndIndustrial
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[4]
Mortgage [Abstract]    
1-4 Family 1,217,000ibcp_Family1To4FairValueDisclosure
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[4] 1,306,000ibcp_Family1To4FairValueDisclosure
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[4]
Resort Lending 139,000ibcp_ResortLendingFairValueDisclosure
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[4]  
Commercial [Abstract]    
Income producing - real estate 786,000ibcp_IncomeProducingRealEstateFairValueDisclosure
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[4] 869,000ibcp_IncomeProducingRealEstateFairValueDisclosure
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[4]
Land, land development & construction - real estate 142,000ibcp_LandLandDevelopmentAndConstructionRealEstateFairValueDisclosure
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[4] 354,000ibcp_LandLandDevelopmentAndConstructionRealEstateFairValueDisclosure
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[4]
Mortgage [Abstract]    
1-4 Family 1,217,000ibcp_Family1To4FairValueDisclosure
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[4] 1,306,000ibcp_Family1To4FairValueDisclosure
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[4]
Resort Lending 139,000ibcp_ResortLendingFairValueDisclosure
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[4]  
Fair Value Measurements [Member] | Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate [Member]    
Commercial [Abstract]    
Income producing - real estate   479,000ibcp_IncomeProducingRealEstateFairValueDisclosure
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[5]
Land, land development & construction - real estate 677,000ibcp_LandLandDevelopmentAndConstructionRealEstateFairValueDisclosure
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[5]
Mortgage [Abstract]    
1-4 Family 102,000ibcp_Family1To4FairValueDisclosure
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[5] 102,000ibcp_Family1To4FairValueDisclosure
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[5]
Resort Lending 427,000ibcp_ResortLendingFairValueDisclosure
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[5] 575,000ibcp_ResortLendingFairValueDisclosure
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[5]
Commercial [Abstract]    
Income producing - real estate   479,000ibcp_IncomeProducingRealEstateFairValueDisclosure
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[5]
Land, land development & construction - real estate 677,000ibcp_LandLandDevelopmentAndConstructionRealEstateFairValueDisclosure
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[5] 737,000ibcp_LandLandDevelopmentAndConstructionRealEstateFairValueDisclosure
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[5]
Mortgage [Abstract]    
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Resort Lending 427,000ibcp_ResortLendingFairValueDisclosure
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Installment [Abstract]    
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[5]
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]    
Assets [Abstract]    
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Assets [Abstract]    
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Assets [Abstract]    
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Assets [Abstract]    
Securities available for sale 0us-gaap_AvailableForSaleSecurities
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Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Recurring [Member] | Corporate [Member]    
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ASSETS [Abstract]    
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[3]
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Commercial [Abstract]    
Income producing - real estate 0ibcp_IncomeProducingRealEstateFairValueDisclosure
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Mortgage [Abstract]    
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Commercial [Abstract]    
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Mortgage [Abstract]    
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Resort Lending 0ibcp_ResortLendingFairValueDisclosure
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Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate [Member]    
Commercial [Abstract]    
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Mortgage [Abstract]    
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Installment [Abstract]    
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Significant Other Observable Inputs (Level 2) [Member]    
Assets [Abstract]    
Trading securities 0us-gaap_TradingSecurities
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533,178,000us-gaap_AvailableForSaleSecurities
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619,000us-gaap_DerivativeAssets
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Liabilities [Abstract]    
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366,000us-gaap_DerivativeLiabilities
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Assets [Abstract]    
Trading securities 0us-gaap_TradingSecurities
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Derivatives 1,268,000us-gaap_DerivativeAssets
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Liabilities [Abstract]    
Derivatives 666,000us-gaap_DerivativeLiabilities
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[2]
Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | U.S. Agency [Member]    
Assets [Abstract]    
Securities available for sale 35,529,000us-gaap_AvailableForSaleSecurities
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Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | U.S. Agency Residential Mortgage-Backed [Member]    
Assets [Abstract]    
Securities available for sale 234,254,000us-gaap_AvailableForSaleSecurities
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257,558,000us-gaap_AvailableForSaleSecurities
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Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | U.S. Agency Commercial Mortgage-Backed [Member]    
Assets [Abstract]    
Securities available for sale 33,081,000us-gaap_AvailableForSaleSecurities
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Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Private Label Residential Mortgage-Backed [Member]    
Assets [Abstract]    
Securities available for sale 5,820,000us-gaap_AvailableForSaleSecurities
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Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Other Asset Backed [Member]    
Assets [Abstract]    
Securities available for sale 95,191,000us-gaap_AvailableForSaleSecurities
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Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Obligations of States and Political Subdivisions [Member]    
Assets [Abstract]    
Securities available for sale 142,788,000us-gaap_AvailableForSaleSecurities
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143,415,000us-gaap_AvailableForSaleSecurities
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Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Corporate [Member]    
Assets [Abstract]    
Securities available for sale 22,661,000us-gaap_AvailableForSaleSecurities
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22,664,000us-gaap_AvailableForSaleSecurities
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Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Recurring [Member] | Trust Preferred [Member]    
Assets [Abstract]    
Securities available for sale 2,438,000us-gaap_AvailableForSaleSecurities
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Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Nonrecurring [Member]    
ASSETS [Abstract]    
Capitalized mortgage loan servicing rights 0ibcp_CapitalizedMortgageLoanServicingRightsFairValueDisclosure
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Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member]    
Commercial [Abstract]    
Income producing - real estate 0ibcp_IncomeProducingRealEstateFairValueDisclosure
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Land, land development & construction - real estate 0ibcp_LandLandDevelopmentAndConstructionRealEstateFairValueDisclosure
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Mortgage [Abstract]    
1-4 Family 0ibcp_Family1To4FairValueDisclosure
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[4] 0ibcp_Family1To4FairValueDisclosure
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Resort Lending 0ibcp_ResortLendingFairValueDisclosure
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Commercial [Abstract]    
Income producing - real estate 0ibcp_IncomeProducingRealEstateFairValueDisclosure
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Mortgage [Abstract]    
1-4 Family 0ibcp_Family1To4FairValueDisclosure
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[4] 0ibcp_Family1To4FairValueDisclosure
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Resort Lending 0ibcp_ResortLendingFairValueDisclosure
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Significant Other Observable Inputs (Level 2) [Member] | Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate [Member]    
Commercial [Abstract]    
Income producing - real estate   0ibcp_IncomeProducingRealEstateFairValueDisclosure
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Mortgage [Abstract]    
1-4 Family 0ibcp_Family1To4FairValueDisclosure
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Resort Lending 0ibcp_ResortLendingFairValueDisclosure
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[5] 0ibcp_ResortLendingFairValueDisclosure
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Commercial [Abstract]    
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Mortgage [Abstract]    
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Resort Lending 0ibcp_ResortLendingFairValueDisclosure
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Installment [Abstract]    
Home equity - 1st lien   0ibcp_HomeEquityInstallment1StLienFairValueDisclosure
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Assets [Abstract]    
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Assets [Abstract]    
Trading securities 0us-gaap_TradingSecurities
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[1] 0us-gaap_DerivativeAssets
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[1]
Liabilities [Abstract]    
Derivatives 0us-gaap_DerivativeLiabilities
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[2]
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member] | U.S. Agency [Member]    
Assets [Abstract]    
Securities available for sale 0us-gaap_AvailableForSaleSecurities
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Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member] | U.S. Agency Residential Mortgage-Backed [Member]    
Assets [Abstract]    
Securities available for sale 0us-gaap_AvailableForSaleSecurities
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Assets [Abstract]    
Securities available for sale 0us-gaap_AvailableForSaleSecurities
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Assets [Abstract]    
Securities available for sale 0us-gaap_AvailableForSaleSecurities
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Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member] | Other Asset Backed [Member]    
Assets [Abstract]    
Securities available for sale 0us-gaap_AvailableForSaleSecurities
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Assets [Abstract]    
Securities available for sale 0us-gaap_AvailableForSaleSecurities
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Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member] | Corporate [Member]    
Assets [Abstract]    
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Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Recurring [Member] | Trust Preferred [Member]    
Assets [Abstract]    
Securities available for sale 0us-gaap_AvailableForSaleSecurities
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Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Nonrecurring [Member]    
ASSETS [Abstract]    
Capitalized mortgage loan servicing rights 8,129,000ibcp_CapitalizedMortgageLoanServicingRightsFairValueDisclosure
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[3]
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Nonrecurring [Member] | Impaired Loans [Member]    
Commercial [Abstract]    
Income producing - real estate 786,000ibcp_IncomeProducingRealEstateFairValueDisclosure
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[4] 869,000ibcp_IncomeProducingRealEstateFairValueDisclosure
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[4]
Land, land development & construction - real estate 142,000ibcp_LandLandDevelopmentAndConstructionRealEstateFairValueDisclosure
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[4]
Commercial and industrial 2,511,000us-gaap_LoansReceivableCommercialAndIndustrial
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[4] 2,601,000us-gaap_LoansReceivableCommercialAndIndustrial
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[4]
Mortgage [Abstract]    
1-4 Family 1,217,000ibcp_Family1To4FairValueDisclosure
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[4] 1,306,000ibcp_Family1To4FairValueDisclosure
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[4]
Resort Lending 139,000ibcp_ResortLendingFairValueDisclosure
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[4]  
Commercial [Abstract]    
Income producing - real estate 786,000ibcp_IncomeProducingRealEstateFairValueDisclosure
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[4] 869,000ibcp_IncomeProducingRealEstateFairValueDisclosure
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[4]
Land, land development & construction - real estate 142,000ibcp_LandLandDevelopmentAndConstructionRealEstateFairValueDisclosure
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[4]
Mortgage [Abstract]    
1-4 Family 1,217,000ibcp_Family1To4FairValueDisclosure
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[4] 1,306,000ibcp_Family1To4FairValueDisclosure
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[4]
Resort Lending 139,000ibcp_ResortLendingFairValueDisclosure
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[4]  
Significant Unobservable Inputs (Level 3) [Member] | Fair Value, Measurements, Nonrecurring [Member] | Other Real Estate [Member]    
Commercial [Abstract]    
Income producing - real estate   479,000ibcp_IncomeProducingRealEstateFairValueDisclosure
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[5]
Land, land development & construction - real estate 677,000ibcp_LandLandDevelopmentAndConstructionRealEstateFairValueDisclosure
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[5] 737,000ibcp_LandLandDevelopmentAndConstructionRealEstateFairValueDisclosure
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= ibcp_OtherRealEstateMember
[5]
Mortgage [Abstract]    
1-4 Family 102,000ibcp_Family1To4FairValueDisclosure
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[5] 102,000ibcp_Family1To4FairValueDisclosure
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[5]
Resort Lending 427,000ibcp_ResortLendingFairValueDisclosure
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[5] 575,000ibcp_ResortLendingFairValueDisclosure
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[5]
Commercial [Abstract]    
Income producing - real estate   479,000ibcp_IncomeProducingRealEstateFairValueDisclosure
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= ibcp_OtherRealEstateMember
[5]
Land, land development & construction - real estate 677,000ibcp_LandLandDevelopmentAndConstructionRealEstateFairValueDisclosure
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[5] 737,000ibcp_LandLandDevelopmentAndConstructionRealEstateFairValueDisclosure
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/ us-gaap_MortgageLoansOnRealEstateLoanTypeAxis
= ibcp_OtherRealEstateMember
[5]
Mortgage [Abstract]    
1-4 Family 102,000ibcp_Family1To4FairValueDisclosure
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[5] 102,000ibcp_Family1To4FairValueDisclosure
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[5]
Resort Lending 427,000ibcp_ResortLendingFairValueDisclosure
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[5] 575,000ibcp_ResortLendingFairValueDisclosure
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= us-gaap_FairValueMeasurementsNonrecurringMember
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[5]
Installment [Abstract]    
Home equity - 1st lien   $ 13,000ibcp_HomeEquityInstallment1StLienFairValueDisclosure
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[5]
[1] Included in accrued income and other assets.
[2] Included in accrued expenses and other liabilities.
[3] Only includes servicing rights that are carried at fair value due to recognition of a valuation allowance.
[4] Only includes impaired loans with specific loss allocations based on collateral value.
[5] Only includes other real estate with subsequent write downs to fair value.