TDR's and Other Pertinent Information (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Summary of Troubled Debt Restructurings and other pertinent information
Tdrs Recorded Investment On Accrual Status	$ 11,278
Tdrs Recorded Investment On Nonaccrual Status	11,520
Financing Receivable Recorded Investment Trouble Debt Restructuring	22,798
Additional Commitments To Lend To Borrower For Trouble Debt Restructuring	$ 64

Additional commitments to lend to a borrower for trouble debt restructuring.

No definition available.

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Balance Type:	debit
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Financing receivable recorded investment trouble debt restructuring.

No definition available.

Name:	indb_FinancingReceivableRecordedInvestmentTroubleDebtRestructuring
Namespace Prefix:	indb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
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Summary of troubled debt restructurings and other pertinent information.

No definition available.

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Troubled Debt Restructurings recorded investment that are on accrual status as of the balance sheet date.

No definition available.

Name:	indb_TdrsRecordedInvestmentOnAccrualStatus
Namespace Prefix:	indb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Troubled Debt Restructurings recorded investment that are on nonaccrual status as of the balance sheet date.

No definition available.

Name:	indb_TdrsRecordedInvestmentOnNonaccrualStatus
Namespace Prefix:	indb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant