INVESTMENTS - Additional Information (Details) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2026 USD ($)	Sep. 30, 2025 USD ($)	Sep. 30, 2026 USD ($) entity	Sep. 30, 2025 USD ($)	Dec. 31, 2025 USD ($) entity
Gain (Loss) on Securities [Line Items]
Proceeds from Sale of Debt Securities, Available-for-sale	$ 15,500	$ 189,300	$ 575,963	$ 353,863
Debt Securities, Available-for-sale, Realized Gain		3,400	7,100	3,500
Available-for-sale Securities, Gross Realized Losses		0		10,000
Debt Securities, Held-to-maturity, Allowance for Credit Loss	$ 0		$ 0		$ 0
NumberOfSecuritiesInSecurityPortfolio	849		849		949
NumberOfSecuritiesInUnrealizedLossPosition	789		789		533
Debt Securities, Held-to-maturity, Nonaccrual	$ 0		$ 0		$ 0
Net gain (loss) on investment securities	247	(42)	(1,350)	(9,748)
Debt Securities, Available-for-Sale, Unrealized Loss Position	4,361,671		4,361,671		2,110,835
Debt Securities, Unrealized Gain (Loss)			$ 800		$ 9,800
Debt Securities, Available-for-Sale, Realized Gain (Loss), Number \| entity			3		6
Debt Securities, Realized Gain (Loss)	0	$ 3,400	$ 8,300	$ 3,400
Financial Instrument, Other
Gain (Loss) on Securities [Line Items]
Debt Securities, Available-for-Sale, Unrealized Loss Position	$ 14,100		$ 14,100		$ 20,900

Debt Securities, Available-for-Sale, Realized Gain (Loss), Number

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The total number of securities included in the investment securities portfolio.

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The total number of securities included in the investment securities portfolio that include net accumulated unrealized losses.

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Amount of unrealized and realized gain (loss) on investment in debt and equity securities.

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