Name:	ibcp_CreditRatingsOfOfInsurerOrRiskRetentionGroupCounterpartiesAbstract
Namespace Prefix:	ibcp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Represents the FICO score of loans by category.

No definition available.

Name:	ibcp_CreditScore500To549
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the FICO score of loans by category.

No definition available.

Name:	ibcp_CreditScore550To599
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the FICO score of loans by category.

No definition available.

Name:	ibcp_CreditScore600To649
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the FICO score of loans by category.

No definition available.

Name:	ibcp_CreditScore650To699
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the FICO score of loans by category.

No definition available.

Name:	ibcp_CreditScore700To749
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the FICO score of loans by category.

No definition available.

Name:	ibcp_CreditScore750To799
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Total recorded investments by credit score.

No definition available.

Name:	ibcp_CreditScoreByInvestment
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the FICO score of loans by category.

No definition available.

Name:	ibcp_CreditScoreUnder500
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents loans categorized as unknown when the FICO credit score is not known.

No definition available.

Name:	ibcp_CreditScoreUnknown
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Represents the FICO score of loans by category.

No definition available.

Name:	ibcp_EightHundredsAndAbove
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

Name:	ibcp_LoanRatingsCreditScoresByLoanClassAbstract
Namespace Prefix:	ibcp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Total payment plan receivable.

No definition available.

Name:	ibcp_PaymentPlanReceivable
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Class of financing receivables related to other payment plan receivable financing receivables.

No definition available.

Name:	ibcp_PaymentPlanReceivableOtherAssets
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Class of financing receivables related to partial refund payment plan receivable financing receivables.

No definition available.

Name:	ibcp_PaymentPlanReceivablePartialRefund
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Class of financing receivables related to full refund payment plan receivable financing receivables.

No definition available.

Name:	ibcp_PaymentPlanReceivablesFullRefund
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

The percentage of outstanding payment plan receivables that a third party insurer or risk retention group is obligated to pay.

No definition available.

Name:	ibcp_SubsidiaryOutstandingPaymentPlanInsuredByThirdParty
Namespace Prefix:	ibcp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

The percentage of outstanding payment plan receivables that a third party insurer or risk retention group is obligated to pay upon cancellation only with respect to the unearned portion previously funded to the administrator.

No definition available.

Name:	ibcp_SubsidiaryOutstandingPaymentPlanInsuredByThirdPartyTwo
Namespace Prefix:	ibcp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Amount before allowance of loans issued to agricultural, commercial and industrial, and financial institutions. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.7(a)(1))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5066-111524

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

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Namespace Prefix:
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Name:	us-gaap_CreditRatingAMBestAxis=us-gaap_AMBestARatingMember
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Name:	us-gaap_CreditRatingAMBestAxis=us-gaap_AMBestAMinusRatingMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_CreditRatingAMBestAxis=ibcp_NotRatedMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_InternalCreditAssessmentAxis=ibcp_NonWatch16Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_InternalCreditAssessmentAxis=ibcp_Watch78Member
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_InternalCreditAssessmentAxis=ibcp_SubstandardAccrual9Member
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_InternalCreditAssessmentAxis=ibcp_NonAccrual1011Member
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=ibcp_CommercialIncomeProducingRealEstateReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=ibcp_CommercialLandLandDevelopmentRealEstateConstructionFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_ResidentialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=ibcp_Family14Member
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=ibcp_ResortLendingMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=ibcp_HomeEquityFirstLienMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=ibcp_HomeEquitySecondLienMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=ibcp_PurchasedLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=ibcp_InstallmentPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=ibcp_LoansNotSecuredByRealEstateMember
Namespace Prefix:
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