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BORROWINGS - Long-term Borrowings - Narrative (Details) - USD ($)		12 Months Ended
	Dec. 22, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Sep. 05, 2025	Jun. 15, 2025	Mar. 12, 2025
Debt Instrument [Line Items]
Loss on extinguishment of debt		$ 9,000,000	$ 2,000,000	$ 0
Minimum deposit		$ 212,000,000	$ 211,000,000
Purchase Money Note
Debt Instrument [Line Items]
Partial prepayment	$ 2,490,000,000
Loss on extinguishment of debt	$ 9,000,000
Parent | Fixed-to-Fixed Subordinated Notes at 5.600% | Subordinated Debt
Debt Instrument [Line Items]
Debt instrument, face amount					$ 600,000,000
Debt instrument, stated interest rate		5.60%			5.60%
Parent | Fixed-to-Floating Senior Notes at 5.231% | Senior Notes
Debt Instrument [Line Items]
Debt instrument, face amount							$ 500,000,000
Debt instrument, stated interest rate		5.231%					5.231%
Parent | Fixed-to-Fixed Subordinated Notes at 6.254% | Subordinated Debt
Debt Instrument [Line Items]
Debt instrument, face amount							$ 750,000,000
Debt instrument, stated interest rate		6.254%					6.254%
Parent | Fixed-to-Floating Subordinated Notes at 3.375% | Subordinated Debt
Debt Instrument [Line Items]
Debt instrument, face amount						$ 350,000,000
Debt instrument, stated interest rate		3.375%				3.375%

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