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

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Amount of the collateral pledged in support of federal home loan bank advances outstanding.

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Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

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Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

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Dividends received on equity and other investments during the current period.

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Borrowed Funds - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank stock, at cost	$ 41,363	$ 10,904
Dividends received from investment in FHLB of Boston	300	200	$ 400
Federal Home Loan Bank of Boston
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank stock, at cost	41,400	10,900
Federal Home Loan Bank of Boston \| Short-term FHLB advances
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank, available and unused borrowing capacity	2,000,000	1,800,000
Federal Home Loan Bank of Boston \| Short-term FHLB advances \| Residential Mortgage Backed Securities
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank, advances secured by mortgage-backed securities	1,500,000	1,000,000
Federal Home Loan Bank of Boston \| Short-term FHLB advances \| Commercial Mortgage Backed Securities
Federal Home Loan Bank, Advances [Line Items]
Federal Home Loan Bank, advances secured by mortgage-backed securities	1,200,000	888,300
Federal Reserve Bank Advances
Federal Home Loan Bank, Advances [Line Items]
Federal Reserve Discount Window, available and unused borrowing capacity	$ 538,900	$ 455,300