Accounting Policies - Capitalized Mortgage Loan Servicing Rights (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Mortgage Loan Servicing Rights [Abstract]
Mortgage loan servicing fees	$ 8.6	$ 7.9	$ 6.9

Fees from servicing mortgage loans that have been sold.

No definition available.

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