Mergers and Acquisitions - Schedule of Difference Between the Purchase Price and Par Value of the Assets Acquired (Details) - USD ($) $ in Thousands		12 Months Ended
Jul. 12, 2024	Dec. 31, 2024
Business Acquisition [Line Items]
Allowance for loan losses on PCD loans		$ (55,830)
Cambridge Bancorp
Business Acquisition [Line Items]
Gross amortized cost basis at July 12, 2024	$ 356,148
Allowance for loan losses on PCD loans	(55,830)	$ (55,800)
Interest and liquidity discount	(26,019)
Purchase price of PCD loans (at fair value)	$ 274,299

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.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount, excluding accrued interest, of allowance for credit loss at acquisition date of financing receivable purchased with credit deterioration. Excludes net investment in lease.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Amount at par value of financing receivable purchased with credit deterioration.

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Amount of discount (premium) attributable to other factors on financing receivable purchased with credit deterioration.

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