RESTRICTIONS ON CASH AND DUE FROM BANKS (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013
RESTRICTIONS ON CASH AND DUE FROM BANKS [Abstract]
Average reserve balances maintained	$ 15.3	$ 24.5
Reserve balances related to investment security transactions and merchant payment processing operations	$ 2.8	$ 2.4

Bank is required to maintain reserve balances in the form of vault cash and non-interest earning balances with the FRB. The amount refers to average reserve balances to be maintained.

No definition available.

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