XML 135 R112.htm IDEA: XBRL DOCUMENT
v3.25.0.1

Recurring and Nonrecurring basis (Details) - USD ($) | Dec. 31, 2024 | Dec. 31, 2023
--- | --- | ---
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Trading |  | $ 4,245,000 | $ 4,987,000
Equity Securities, FV-NI |  | 21,204,000 | 22,510,000
Debt Securities, Available-for-Sale |  | 1,250,944,000 | 1,334,256,000
US Government Agencies Debt Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 209,660,000 | 207,138,000
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 378,161,000 | 277,047,000
Pooled Trust Preferred Securities Issued By Banks And Insurers [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 1,095,000 | 1,018,000
Small Business Administration Pooled Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 40,838,000 | 46,572,000
US Treasury Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 592,001,000 | 769,102,000
Fair Value, Recurring [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Trading |  | 4,245,000 | 4,987,000
Assets and liabilities measured at fair value on a recurring basis |  |  |
Assets and Liabilities Fair Value Disclosure Recurring |  | 1,263,867,000 | 1,338,201,000
Fair Value, Recurring [Member] | Equity Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Equity Securities, FV-NI |  | 21,204,000 | 22,510,000
Fair Value, Recurring [Member] | US Government Agencies Debt Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 209,660,000 | 207,138,000
Fair Value, Recurring [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 378,161,000 | 277,047,000
Fair Value, Recurring [Member] | Collateralized Mortgage Obligations [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 28,995,000 | 33,189,000
Fair Value, Recurring [Member] | Municipal Bonds [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 194,000 | 190,000
Fair Value, Recurring [Member] | Pooled Trust Preferred Securities Issued By Banks And Insurers [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 1,095,000 | 1,018,000
Fair Value, Recurring [Member] | Small Business Administration Pooled Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 40,838,000 | 46,572,000
Fair Value, Recurring [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Loans Held-for-sale, Fair Value Disclosure |  | 7,271,000 | 6,368,000
Fair Value, Recurring [Member] | Derivative Financial Instruments, Assets [Member] |  |  |
Assets and liabilities measured at fair value on a recurring basis |  |  |
Total |  | 103,958,000 | 103,948,000
Fair Value, Recurring [Member] | Derivative Financial Instruments, Liabilities [Member] |  |  |
Assets and liabilities measured at fair value on a recurring basis |  |  |
Financial and Nonfinancial Liabilities, Fair Value Disclosure |  | 123,755,000 | 133,868,000
Fair Value, Recurring [Member] | US Treasury Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 592,001,000 | 769,102,000
Fair Value, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Trading |  | 4,245,000 | 4,987,000
Assets and liabilities measured at fair value on a recurring basis |  |  |
Assets and Liabilities Fair Value Disclosure Recurring |  | 25,449,000 | 27,497,000
Fair Value, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Equity Securities, FV-NI |  | 21,204,000 | 22,510,000
Fair Value, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | US Government Agencies Debt Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 0 | 0
Fair Value, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 0 | 0
Fair Value, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Collateralized Mortgage Obligations [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 0 | 0
Fair Value, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Municipal Bonds [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 0 | 0
Fair Value, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Pooled Trust Preferred Securities Issued By Banks And Insurers [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 0 | 0
Fair Value, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Small Business Administration Pooled Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 0 | 0
Fair Value, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Loans Held-for-sale, Fair Value Disclosure |  |  | 0
Fair Value, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Derivative Financial Instruments, Assets [Member] |  |  |
Assets and liabilities measured at fair value on a recurring basis |  |  |
Total |  |  | 0
Fair Value, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Derivative Financial Instruments, Liabilities [Member] |  |  |
Assets and liabilities measured at fair value on a recurring basis |  |  |
Financial and Nonfinancial Liabilities, Fair Value Disclosure |  | 0 | 0
Fair Value, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | US Treasury Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 0 | 0
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Trading |  | 0 | 0
Assets and liabilities measured at fair value on a recurring basis |  |  |
Assets and Liabilities Fair Value Disclosure Recurring |  | 1,238,418,000 | 1,310,704,000
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Equity Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Equity Securities, FV-NI |  | 0 | 0
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | US Government Agencies Debt Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 209,660,000 | 207,138,000
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 378,161,000 | 277,047,000
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Collateralized Mortgage Obligations [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 28,995,000 | 33,189,000
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Municipal Bonds [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 194,000 | 190,000
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Pooled Trust Preferred Securities Issued By Banks And Insurers [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 1,095,000 | 1,018,000
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Small Business Administration Pooled Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 40,838,000 | 46,572,000
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Loans Held-for-sale, Fair Value Disclosure |  | 7,271,000 | 6,368,000
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Derivative Financial Instruments, Assets [Member] |  |  |
Assets and liabilities measured at fair value on a recurring basis |  |  |
Total |  | 103,958,000 | 103,948,000
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Derivative Financial Instruments, Liabilities [Member] |  |  |
Assets and liabilities measured at fair value on a recurring basis |  |  |
Financial and Nonfinancial Liabilities, Fair Value Disclosure |  | 123,755,000 | 133,868,000
Fair Value, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | US Treasury Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 592,001,000 | 769,102,000
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Trading |  | 0 | 0
Assets and liabilities measured at fair value on a recurring basis |  |  |
Assets and Liabilities Fair Value Disclosure Recurring |  | 0 | 0
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Equity Securities, FV-NI |  | 0 | 0
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | US Government Agencies Debt Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 0 | 0
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 0 | 0
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Collateralized Mortgage Obligations [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 0 | 0
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Municipal Bonds [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 0 | 0
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Pooled Trust Preferred Securities Issued By Banks And Insurers [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 0 | 0
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Small Business Administration Pooled Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 0 | 0
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Disposal Group, Held-for-sale, Not Discontinued Operations [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Loans Held-for-sale, Fair Value Disclosure |  |  | 0
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Derivative Financial Instruments, Assets [Member] |  |  |
Assets and liabilities measured at fair value on a recurring basis |  |  |
Total |  |  | 0
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Derivative Financial Instruments, Liabilities [Member] |  |  |
Assets and liabilities measured at fair value on a recurring basis |  |  |
Financial and Nonfinancial Liabilities, Fair Value Disclosure |  | 0 | 0
Fair Value, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | US Treasury Securities [Member] |  |  |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] |  |  |
Debt Securities, Available-for-Sale |  | 0 | 0
Fair Value, Nonrecurring [Member] |  |  |
Assets and liabilities measured at fair value on a recurring basis |  |  |
Assets And Liabilities Fair Value Disclosure Nonrecurring |  | 43,766,000 | 28,881,000
Fair Value, Nonrecurring [Member] | Collateral Dependent Loans [Member] |  |  |
Assets and liabilities measured at fair value on a recurring basis |  |  |
Assets, Fair Value Disclosure |  | 43,766,000 | 28,881,000
Fair Value, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] |  |  |
Assets and liabilities measured at fair value on a recurring basis |  |  |
Assets And Liabilities Fair Value Disclosure Nonrecurring |  | 0 | 0
Fair Value, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Collateral Dependent Loans [Member] |  |  |
Assets and liabilities measured at fair value on a recurring basis |  |  |
Assets, Fair Value Disclosure |  | 0 | 0
Fair Value, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member] |  |  |
Assets and liabilities measured at fair value on a recurring basis |  |  |
Assets And Liabilities Fair Value Disclosure Nonrecurring |  | 0 | 0
Fair Value, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Collateral Dependent Loans [Member] |  |  |
Assets and liabilities measured at fair value on a recurring basis |  |  |
Assets, Fair Value Disclosure |  | 0 | 0
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] |  |  |
Assets and liabilities measured at fair value on a recurring basis |  |  |
Assets And Liabilities Fair Value Disclosure Nonrecurring |  | 43,766,000 | 28,881,000
Fair Value, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Collateral Dependent Loans [Member] |  |  |
Assets and liabilities measured at fair value on a recurring basis |  |  |
Assets, Fair Value Disclosure | [1] | $ 43,766,000 | $ 28,881,000
[1] | The carrying value of individually assessed collateral dependent loans is based on the lower of amortized cost or fair value of the underlying collateral less costs to sell. The fair value of the underlying collateral is generally determined through independent appraisals, which generally include various Level 3 inputs which are not identifiable. Appraisals may be adjusted by management for qualitative factors such as economic factors and estimated liquidation expenses. The range of these possible adjustments may vary. .

X
- Definition Assets and liabilities, fair value disclosure nonrecurring. + References No definition available. + Details
Name: | indb_AssetsAndLiabilitiesFairValueDisclosureNonrecurring
Namespace Prefix: | indb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Assets and liabilities, fair value disclosure recurring. + References No definition available. + Details
Name: | indb_AssetsAndLiabilitiesFairValueDisclosureRecurring
Namespace Prefix: | indb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of asset recognized for present right to economic benefit. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 100 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-100 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 326 -SubTopic 30 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147479130/326-30-45-1 + Details
Name: | us-gaap_DebtSecuritiesAvailableForSaleExcludingAccruedInterest
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4B -Subparagraph (c) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4B Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4B -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480434/815-10-50-4B Reference 3: http://www.xbrl.org/2003/role/exampleRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 22 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483444/210-20-55-22 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483466/210-20-50-3 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 210 -SubTopic 20 -Name Accounting Standards Codification -Section 55 -Paragraph 7 -Publisher FASB -URI https://asc.fasb.org/1943274/2147483444/210-20-55-7 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 50 -Paragraph 4D -Subparagraph (c)(2) -SubTopic 20 -Topic 860 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481326/860-20-50-4D + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeAsset
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as current. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483467/210-10-45-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 825 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1A -Publisher FASB -URI https://asc.fasb.org/1943274/2147482736/825-10-45-1A + Details
Name: | us-gaap_EquitySecuritiesFvNi
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 55 -Paragraph 100 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482078/820-10-55-100 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 3 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-3 + Details
Name: | us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value of financial and nonfinancial obligations. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
Name: | us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value portion of loans held-for-sale including, but not limited to, mortgage loans and finance receivables. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 + Details
Name: | us-gaap_LoansHeldForSaleFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2)(i) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(2) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (bbb)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 820 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482106/820-10-50-2 Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481830/320-10-45-1 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(2)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1 Reference 7: http://www.xbrl.org/2003/role/exampleRef -Topic 210 -SubTopic 10 -Name Accounting Standards Codification -Section 45 -Paragraph 1 -Subparagraph (f) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483467/210-10-45-1 + Details
Name: | us-gaap_TradingSecuritiesDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentAgenciesDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=indb_PooledTrustPreferredSecuritiesIssuedByBanksAndInsurersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=indb_SmallBusinessAdministrationPooledSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_EquitySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CollateralizedMortgageObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MunicipalBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_DisposalGroupHeldforsaleNotDiscontinuedOperationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_DerivativeFinancialInstrumentsAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsNonrecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=indb_CollateralDependentLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |