Contingent Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Contingent Liabilities [Abstract]
Provision for loss reimbursement on sold loans	$ 110	$ 10
Reserve for loss reimbursement on sold mortgage loans	$ 800		$ 780

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