Borrowings (Narrative) (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Federal Home Loan Bank, Advances, Branch of FHLBB Bank [Line Items]
Federal Home Loan Bank advances	$ 791,000	$ 1,125,000
Federal Home Loan Bank of Boston
Federal Home Loan Bank, Advances, Branch of FHLBB Bank [Line Items]
Federal Home Loan Bank advances	791,000	1,100,000
Unused remaining available borrowing capacity with FHLB	1,100,000	753,000
Unused line of credit with FHLB	40,000	40,000
Standby letter of credit with FHLB	$ 66,000	$ 66,000

Amount of borrowings as of the balance sheet date from the Federal Home Loan Bank, which are primarily used to cover shortages in the required reserve balance and liquidity shortages.

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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

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Amount of advances or credit lines available from the Federal Home Loan Bank (FHLB).

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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The amount remaining to be drawn on at the balance sheet date associated with a standby letter of credit with the FHLB.

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