Assets, including available for sale securities, pledged to secure borrowings.

No definition available.

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

- Definition

Federal Home Loan Bank, Advances, Fixed Rate, Terminated

+ References

No definition available.

+ Details

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

- Definition

Hair cut percentage used on qualifying mortgage and home equity loan collateral.

+ References

No definition available.

+ Details

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Namespace Prefix:	ibcp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents minimum percentage of unpaid principal balance of FHLB advances that needs to be held in the form of federal home loan bank stock.

+ References

No definition available.

+ Details

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Namespace Prefix:	ibcp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents minimum percentage of unpaid principal balance of residential mortgage loans that needs to be held in the form of federal home loan bank stock.

+ References

No definition available.

+ Details

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Namespace Prefix:	ibcp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of advances or credit lines available from the Federal Reserve Bank.

+ References

No definition available.

+ Details

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

- Definition

Refers to the outstanding amount borrowed during the period from the Federal Reserve Bank.

+ References

No definition available.

+ Details

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

- Definition

Refers to the average borrowings amount during the period from the Federal Reserve Bank.

+ References

No definition available.

+ Details

Name:	ibcp_FederalReserveBankAverageBorrowings
Namespace Prefix:	ibcp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Federal Reserve Bank, Interest Expense

+ References

No definition available.

+ Details

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

- Definition

Amount of advances or credit lines available from the Federal Home Loan Bank (FHLB).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22)(b))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(13)(3)(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 942
-SubTopic 470
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478878/942-470-45-1

+ Details

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

- References

No definition available.

+ Details

Name:	us-gaap_FederalHomeLoanBanksAbstract
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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Interest expense incurred during the reporting period on long-term borrowings associated with Federal Home Loan Bank and Federal Reserve Bank advances.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
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OTHER BORROWINGS - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Federal Home Loan Banks [Abstract]
Unused borrowing capacity with FHLB	$ 750,000
Interest expense, federal home loan bank and federal reserve bank advances, long-term	$ 800	$ 2,000	$ 2,400
FHLB stock as a percentage of outstanding advances	4.50%
Available for sale and loans, pledged to secure other borrowings	$ 2,860,000
Federal Home Loan Bank, Advances, Fixed Rate
Federal Home Loan Banks [Abstract]
FHLB, advances, fixed rate, terminated		50,000
Federal reserve bank advances
Federal Home Loan Banks [Abstract]
FRB	0	0
Average borrowings	100	200	4,500
Unused borrowing capacity	1,240,000
Interest expense	$ 4	$ 13	$ 188
Minimum
Federal Home Loan Banks [Abstract]
Federal home loan bank, advances, interest rate	125.00%
FHLB stock as a percentage of unpaid principal balance	0.10%
Maximum
Federal Home Loan Banks [Abstract]
Federal home loan bank, advances, interest rate	165.00%