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Securities (Unrealized Loss NOT deemed to be OTTI) (Details) (USD $)
In Thousands, unless otherwise specified
Mar. 31, 2015
holding
Dec. 31, 2014
holding
Summary of gross unrealized losses and fair value of investments    
No of holdings 47indb_AvailableForSaleAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions 80indb_AvailableForSaleAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions
Fair value, less than 12 months $ 17,398indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue $ 64,537indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months (131)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months (467)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months
Fair value, 12 months or longer 104,796indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue 143,949indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months (3,931)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months (5,981)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months
Fair value, Total 122,194indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue 208,486indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss (4,062)indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLoss (6,448)indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLoss
U. S. Government Agency Securities [Member]    
Summary of gross unrealized losses and fair value of investments    
No of holdings   22indb_AvailableForSaleAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Fair value, less than 12 months   21,950indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months   (22)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Fair value, 12 months or longer   0indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months   0indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Fair value, Total   21,950indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss   (22)indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Agency mortgage-backed securities    
Summary of gross unrealized losses and fair value of investments    
No of holdings 12indb_AvailableForSaleAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
17indb_AvailableForSaleAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Fair value, less than 12 months 7,375indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
3,471indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months (40)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
(1)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Fair value, 12 months or longer 4,718indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
42,222indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months (117)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
(692)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Fair value, Total 12,093indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
45,693indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss (157)indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
(693)indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Agency Collateralized Mortgage Obligations [Member]    
Summary of gross unrealized losses and fair value of investments    
No of holdings 12indb_AvailableForSaleAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions
/ us-gaap_DebtSecurityAxis
= us-gaap_CollateralizedDebtObligationsMember
14indb_AvailableForSaleAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions
/ us-gaap_DebtSecurityAxis
= us-gaap_CollateralizedDebtObligationsMember
Fair value, less than 12 months 7,682indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_CollateralizedDebtObligationsMember
35,083indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_CollateralizedDebtObligationsMember
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months (4)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months
/ us-gaap_DebtSecurityAxis
= us-gaap_CollateralizedDebtObligationsMember
(331)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months
/ us-gaap_DebtSecurityAxis
= us-gaap_CollateralizedDebtObligationsMember
Fair value, 12 months or longer 93,437indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_CollateralizedDebtObligationsMember
94,974indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_CollateralizedDebtObligationsMember
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months (2,227)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months
/ us-gaap_DebtSecurityAxis
= us-gaap_CollateralizedDebtObligationsMember
(3,770)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months
/ us-gaap_DebtSecurityAxis
= us-gaap_CollateralizedDebtObligationsMember
Fair value, Total 101,119indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_CollateralizedDebtObligationsMember
130,057indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_CollateralizedDebtObligationsMember
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss (2,231)indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_CollateralizedDebtObligationsMember
(4,101)indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_CollateralizedDebtObligationsMember
Single issuer trust preferred securities issued by banks and insurers    
Summary of gross unrealized losses and fair value of investments    
No of holdings 1indb_AvailableForSaleAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions
/ us-gaap_DebtSecurityAxis
= indb_SingleIssuerTrustPreferredSecuritiesIssuedByBanksMember
2indb_AvailableForSaleAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions
/ us-gaap_DebtSecurityAxis
= indb_SingleIssuerTrustPreferredSecuritiesIssuedByBanksMember
Fair value, less than 12 months 1,076indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= indb_SingleIssuerTrustPreferredSecuritiesIssuedByBanksMember
2,553indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= indb_SingleIssuerTrustPreferredSecuritiesIssuedByBanksMember
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months (10)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months
/ us-gaap_DebtSecurityAxis
= indb_SingleIssuerTrustPreferredSecuritiesIssuedByBanksMember
(39)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months
/ us-gaap_DebtSecurityAxis
= indb_SingleIssuerTrustPreferredSecuritiesIssuedByBanksMember
Fair value, 12 months or longer 0indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= indb_SingleIssuerTrustPreferredSecuritiesIssuedByBanksMember
0indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= indb_SingleIssuerTrustPreferredSecuritiesIssuedByBanksMember
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months 0indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months
/ us-gaap_DebtSecurityAxis
= indb_SingleIssuerTrustPreferredSecuritiesIssuedByBanksMember
0indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months
/ us-gaap_DebtSecurityAxis
= indb_SingleIssuerTrustPreferredSecuritiesIssuedByBanksMember
Fair value, Total 1,076indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= indb_SingleIssuerTrustPreferredSecuritiesIssuedByBanksMember
2,553indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= indb_SingleIssuerTrustPreferredSecuritiesIssuedByBanksMember
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss (10)indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLoss
/ us-gaap_DebtSecurityAxis
= indb_SingleIssuerTrustPreferredSecuritiesIssuedByBanksMember
(39)indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLoss
/ us-gaap_DebtSecurityAxis
= indb_SingleIssuerTrustPreferredSecuritiesIssuedByBanksMember
Pooled trust preferred securities issued by banks and insurers    
Summary of gross unrealized losses and fair value of investments    
No of holdings 2indb_AvailableForSaleAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions
/ us-gaap_DebtSecurityAxis
= indb_PooledTrustPreferredSecuritiesIssuedByBanksAndInsurersMember
2indb_AvailableForSaleAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions
/ us-gaap_DebtSecurityAxis
= indb_PooledTrustPreferredSecuritiesIssuedByBanksAndInsurersMember
Fair value, less than 12 months 0indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= indb_PooledTrustPreferredSecuritiesIssuedByBanksAndInsurersMember
0indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= indb_PooledTrustPreferredSecuritiesIssuedByBanksAndInsurersMember
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months 0indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months
/ us-gaap_DebtSecurityAxis
= indb_PooledTrustPreferredSecuritiesIssuedByBanksAndInsurersMember
0indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months
/ us-gaap_DebtSecurityAxis
= indb_PooledTrustPreferredSecuritiesIssuedByBanksAndInsurersMember
Fair value, 12 months or longer 2,549indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= indb_PooledTrustPreferredSecuritiesIssuedByBanksAndInsurersMember
2,681indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= indb_PooledTrustPreferredSecuritiesIssuedByBanksAndInsurersMember
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months (1,444)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months
/ us-gaap_DebtSecurityAxis
= indb_PooledTrustPreferredSecuritiesIssuedByBanksAndInsurersMember
(1,356)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months
/ us-gaap_DebtSecurityAxis
= indb_PooledTrustPreferredSecuritiesIssuedByBanksAndInsurersMember
Fair value, Total 2,549indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= indb_PooledTrustPreferredSecuritiesIssuedByBanksAndInsurersMember
2,681indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= indb_PooledTrustPreferredSecuritiesIssuedByBanksAndInsurersMember
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss (1,444)indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLoss
/ us-gaap_DebtSecurityAxis
= indb_PooledTrustPreferredSecuritiesIssuedByBanksAndInsurersMember
(1,356)indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLoss
/ us-gaap_DebtSecurityAxis
= indb_PooledTrustPreferredSecuritiesIssuedByBanksAndInsurersMember
Equity securities    
Summary of gross unrealized losses and fair value of investments    
No of holdings 20indb_AvailableForSaleAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions
/ us-gaap_DebtSecurityAxis
= us-gaap_EquitySecuritiesMember
23indb_AvailableForSaleAndHeldToMaturitySecuritiesInUnrealizedLossPositionsQualitativeDisclosureNumberOfPositions
/ us-gaap_DebtSecurityAxis
= us-gaap_EquitySecuritiesMember
Fair value, less than 12 months 1,265indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_EquitySecuritiesMember
1,480indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_EquitySecuritiesMember
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for less than 12 months (77)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months
/ us-gaap_DebtSecurityAxis
= us-gaap_EquitySecuritiesMember
(74)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionforlessthan12months
/ us-gaap_DebtSecurityAxis
= us-gaap_EquitySecuritiesMember
Fair value, 12 months or longer 4,092indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_EquitySecuritiesMember
4,072indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_EquitySecuritiesMember
Unrealized loss position for available for sale and held to maturity securities in a continuous loss position for more than 12 months (143)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months
/ us-gaap_DebtSecurityAxis
= us-gaap_EquitySecuritiesMember
(163)indb_Unrealizedlosspositionforavailableforsaleandheldtomaturitysecuritiesinacontinuouslosspositionformorethan12months
/ us-gaap_DebtSecurityAxis
= us-gaap_EquitySecuritiesMember
Fair value, Total 5,357indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_EquitySecuritiesMember
5,552indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionFairValue
/ us-gaap_DebtSecurityAxis
= us-gaap_EquitySecuritiesMember
Available for Sale and Held to Maturity Securities Continuous Unrealized Loss Position Aggregate Loss $ (220)indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_EquitySecuritiesMember
$ (237)indb_AvailableForSaleAndHeldToMaturitySecuritiesContinuousUnrealizedLossPositionAggregateLoss
/ us-gaap_DebtSecurityAxis
= us-gaap_EquitySecuritiesMember