STOCK BASED COMPENSATION (Details Textual) (Stock options [Member])	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annualized estimated forfeitures	3.50%	5.00%	5.00%

Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Annualized Estimated Forfeitures

No definition available.

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Namespace Prefix:	indb_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration