XML 154 R129.htm IDEA: XBRL DOCUMENT
v3.10.0.1

OTHER COMPREHENSIVE LOSS (Details Textual) - USD ($) | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2009
--- | --- | --- | ---
Equity [Abstract] |  |  |
Gain on interest rate swaps | $ 137,000 | $ 281,000 | $ 1,400,000

X
- Definition Deferred gain or loss on cash flow hedge. + References No definition available. + Details
Name: | indb_DeferredGainLossOnCashFlowHedge
Namespace Prefix: | indb_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_EquityAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration