Name:	ibcp_ContractDisclosureOffBalanceSheetRisksAmount
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Refers to variable rate on standby letters of credit.

No definition available.

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

- References

No definition available.

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

The amount refers to class notification costs and certain other estimated expenses.

No definition available.

Name:	ibcp_NotificationCostsAndOtherEstimatedExpenses
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Non interest provision for loss reimbursement on sold loans.

No definition available.

Name:	ibcp_ProvisionForLossReimbursementOnSoldLoans
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Represents receivables related to a total amount of receivables purchased through a business combination that are subject to an indemnification agreement between the seller and the purchaser.

No definition available.

Name:	ibcp_ReceivableBalanceSubjectToIndemnification
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Reserve balance as of the reporting date for loss reimbursements on sold mortgage loans.

No definition available.

Name:	ibcp_ReserveForLossReimbursementOnSoldLoans
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of litigation expense, including but not limited to legal, forensic, accounting, and investigative fees.

No definition available.

Name:	us-gaap_LitigationSettlementExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The amount of cash paid for the settlement of litigation or for other legal issues during the period.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 25
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3536-108585

Name:	us-gaap_PaymentsForLegalSettlements
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Name:	us-gaap_BusinessAcquisitionAxis=ibcp_TCSBBancorpIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_CommitmentsToExtendCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_StandbyLettersOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: