DERIVATIVE FINANCIAL INSTRUMENTS - Schedule of Derivative Instruments Fair Value Hedges (Details) - Qualifying Hedges - Interest rate contracts - Fair Value Hedges - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Net gain on fair value hedges	$ 1	$ (1)	$ 2	$ (1)
Deposits
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Recognized on derivatives	0	(1)	0	(1)
Recognized on hedged item	0	1	0	1
Borrowings
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Recognized on derivatives	0	(1)	0	(6)
Recognized on hedged item	$ 1	$ 0	$ 2	$ 5