XML 47 R59.htm IDEA: XBRL DOCUMENT
v3.20.1

Loans, Allowance for Loan Losses and Credit Quality (Internal Risk-Rating Categories for the Commercial Portfolio) (Details) - USD ($) | 3 Months Ended |
--- | --- | ---
Mar. 31, 2020 | Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items] |  |
Significant Advanced Considered For Risk Rating Change | $ 50,000 |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | $ 6,119,185,000
Commercial and Industrial [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 1,395,036,000
Commercial Real Estate [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 4,002,359,000
Commercial Construction [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 547,293,000
Small Business [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 174,497,000
PASS [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 5,848,531,000
PASS [Member] | Commercial and Industrial [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 1,274,155,000
PASS [Member] | Commercial Real Estate [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 3,860,555,000
PASS [Member] | Commercial Construction [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 542,608,000
PASS [Member] | Small Business [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 171,213,000
POTENTIAL WEAKNESS [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 164,416,000
POTENTIAL WEAKNESS [Member] | Commercial and Industrial [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 63,485,000
POTENTIAL WEAKNESS [Member] | Commercial Real Estate [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 97,268,000
POTENTIAL WEAKNESS [Member] | Commercial Construction [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 2,247,000
POTENTIAL WEAKNESS [Member] | Small Business [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 1,416,000
DEFINITE WEAKNESS-LOSS UNLIKELY [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 106,238,000
DEFINITE WEAKNESS-LOSS UNLIKELY [Member] | Commercial and Industrial [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 57,396,000
DEFINITE WEAKNESS-LOSS UNLIKELY [Member] | Commercial Real Estate [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 44,536,000
DEFINITE WEAKNESS-LOSS UNLIKELY [Member] | Commercial Construction [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 2,438,000
DEFINITE WEAKNESS-LOSS UNLIKELY [Member] | Small Business [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 1,868,000
PARTIAL LOSS PROBABLE [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 0
PARTIAL LOSS PROBABLE [Member] | Commercial and Industrial [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 0
PARTIAL LOSS PROBABLE [Member] | Commercial Real Estate [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 0
PARTIAL LOSS PROBABLE [Member] | Commercial Construction [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 0
PARTIAL LOSS PROBABLE [Member] | Small Business [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 0
DEFINITE LOSS [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 0
DEFINITE LOSS [Member] | Commercial and Industrial [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 0
DEFINITE LOSS [Member] | Commercial Real Estate [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 0
DEFINITE LOSS [Member] | Commercial Construction [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | 0
DEFINITE LOSS [Member] | Small Business [Member] |  |
Internal risk-rating categories for the Company's commercial portfolio |  |
TOTAL |  | $ 0

X
- Definition Significant Advanced Considered For Risk Rating Change + References No definition available. + Details
Name: | indb_SignificantAdvancedConsideredForRiskRatingChange
Namespace Prefix: | indb_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Summary of internal risk rating categories. + References No definition available. + Details
Name: | indb_SummaryOfInternalRiskRatingCategoriesAbstract
Namespace Prefix: | indb_
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 No definition available. + Details
Name: | us-gaap_FinancingReceivableAllowanceForCreditLossesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after allowance for credit loss, of financing receivable. Excludes financing receivable covered under loss sharing agreement. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919230-210447 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(3)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=118952595&loc=d3e4428-111522 + Details
Name: | us-gaap_NotesReceivableNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=indb_CommercialAndIndustrialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_CommercialRealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=us-gaap_ConstructionLoansMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=indb_SmallBusinessMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=us-gaap_PassMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=indb_PotentialWeaknessMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=indb_DefiniteWeaknessLossUnlikelyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=indb_PartialLossProbableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InternalCreditAssessmentAxis=indb_DefiniteLossMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |