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Loans Receivable, Allowance for Credit Losses and Credit Quality - Consumer loan pools (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Loans Receivable, Allowance for Credit Losses and Credit Quality
Loans receivable, net of deferred fees	$ 4,716,129		$ 4,716,129		$ 4,333,152
Carrying value of loans pledged to secure advances	41,453		41,453		120,835
Investment securities pledged | FHLB
Loans Receivable, Allowance for Credit Losses and Credit Quality
Carrying value of loans pledged to secure advances	1,230,000		1,230,000		1,240,000
Consumer
Loans Receivable, Allowance for Credit Losses and Credit Quality
Loans purchased	20,300	$ 13,300	34,700	$ 32,900
Gross Loan	203,761		203,761		207,051
Premium (Discount)	(3,801)		(3,801)		(3,910)
Loans receivable, net of deferred fees	199,960		199,960		203,141
Consumer | Student loans
Loans Receivable, Allowance for Credit Losses and Credit Quality
Gross Loan	5,733		5,733		6,954
Premium (Discount)	35		35		42
Loans receivable, net of deferred fees	5,768		5,768		6,996
Consumer | Boat and RV loans
Loans Receivable, Allowance for Credit Losses and Credit Quality
Gross Loan	41,517		41,517		48,147
Premium (Discount)	937		937		1,136
Loans receivable, net of deferred fees	42,454		42,454		49,283
Consumer | Automobile loans
Loans Receivable, Allowance for Credit Losses and Credit Quality
Gross Loan	68,307		68,307		52,092
Loans receivable, net of deferred fees	68,307		68,307		52,092
Consumer | Solar panel loans
Loans Receivable, Allowance for Credit Losses and Credit Quality
Gross Loan	50,436		50,436		55,400
Premium (Discount)	(4,758)		(4,758)		(5,073)
Loans receivable, net of deferred fees	45,678		45,678		50,327
Consumer | Home improvement loans
Loans Receivable, Allowance for Credit Losses and Credit Quality
Gross Loan	37,768		37,768		44,458
Premium (Discount)	(15)		(15)		(15)
Loans receivable, net of deferred fees	$ 37,753		$ 37,753		$ 44,443

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- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, Purchase Premium (Discount) of financing receivable. Excludes net investment in lease.

+ References

No definition available.

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-Topic 310
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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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Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable. Excludes net investment in lease.

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Amount of unamortized purchase premium (discount) on financing receivable. Excludes financing receivable covered under loss sharing agreement.

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The cash outflow for the purchase of loan receivable arising from the financing of goods and services.

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