RESTRICTIONS ON CASH AND DUE FROM BANKS (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
RESTRICTIONS ON CASH AND DUE FROM BANKS [Abstract]
Average reserve balances maintained	$ 26.1	$ 23.9
Reserve balances related to visa debit card operations and merchant payment processing operations	$ 2.5	$ 2.1

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