Name:	ibcp_CreditRatingsOfOfInsurerOrRiskRetentionGroupCounterpartiesAbstract
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Data Type:	xbrli:stringItemType
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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_
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Period Type:	instant

Represents the FICO score of loans by category.

No definition available.

Name:	ibcp_CreditScore700To749
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Represents the FICO score of loans by category.

No definition available.

Name:	ibcp_CreditScore750To799
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
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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 the FICO score of loans by category.

No definition available.

Name:	ibcp_EightHundredsAndAbove
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

Name:	ibcp_LoanRatingsCreditScoresByLoanClassAbstract
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Data Type:	xbrli:stringItemType
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Period Type:	duration

Amount before allowance of commercial loans and leases receivable includes, but not limited to, commercial and industrial loans, agricultural loans, mortgage loans, promissory notes, interbank and other loans to financial institutions, draws against credit facilities, trade financing, lease financings. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

No definition available.

Name:	ibcp_LoansReceivableCommercial
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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

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_PaymentPlanReceivableOther
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
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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
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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_SubsidiaryPaymentOutstandingPaymentPlanInsuredByThirdParty
Namespace Prefix:	ibcp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Represents the FICO score of loans categorized as unknown.

No definition available.

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

Recorded investment of consumer mortgage loan receivables secured by residential real estate properties for which formal foreclosure proceedings are in process.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 35
-URI http://asc.fasb.org/extlink&oid=66008989&loc=SL49126937-111524

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Recorded Investment
-URI http://asc.fasb.org/extlink&oid=65880944

Name:	us-gaap_MortgageLoansInProcessOfForeclosureAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

Name:	us-gaap_OtherRealEstateAndForeclosedAssetsAbstract
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Data Type:	xbrli:stringItemType
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Carrying amount as of the balance sheet date of land and buildings obtained through foreclosure proceedings or defeasance in full or partial satisfaction of a debt arrangement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 10
-Section S99
-Paragraph 6
-Subparagraph (SX 210.5-04(c)(Schedule III))
-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5162-111524

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=65884687&loc=d3e4437-111522

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 970
-SubTopic 360
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-28)
-URI http://asc.fasb.org/extlink&oid=6590653&loc=d3e638233-123024

Name:	us-gaap_RealEstateAcquiredThroughForeclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Name:	us-gaap_CreditRatingAMBestAxis=us-gaap_AMBestAPlusRatingMember
Namespace Prefix:
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Name:	us-gaap_CreditRatingAMBestAxis=us-gaap_AMBestARatingMember
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Name:	us-gaap_CreditRatingAMBestAxis=ibcp_NotRatedMember
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Data Type:	na
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Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=us-gaap_CommercialPortfolioSegmentMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_InternalCreditAssessmentAxis=ibcp_NonWatch16Member
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_InternalCreditAssessmentAxis=ibcp_Watch78Member
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Name:	us-gaap_InternalCreditAssessmentAxis=ibcp_SubstandardAccrual9Member
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Data Type:	na
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Name:	us-gaap_InternalCreditAssessmentAxis=ibcp_NonAccrual1011Member
Namespace Prefix:
Data Type:	na
Balance Type:
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=ibcp_CommercialIncomeProducingRealEstateReceivableMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=ibcp_CommercialLandLandDevelopmentRealEstateConstructionFinancingReceivableMember
Namespace Prefix:
Data Type:	na
Balance Type:
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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:
Period Type:

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
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Data Type:	na
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=ibcp_HomeEquitySecondLienMember
Namespace Prefix:
Data Type:	na
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Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=ibcp_PurchasedLoansMember
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Data Type:	na
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Name:	us-gaap_FinancingReceivablePortfolioSegmentAxis=ibcp_InstallmentLoanPortfolioSegmentMember
Namespace Prefix:
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