DERIVATIVES - Schedule of Fair Value Hedges (Details) - Interest rate swap - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Interest And Dividend Income, Investment Securities
Derivative Instruments, Gain (Loss) [Line Items]
Hedged items	$ 12	$ 302	$ 178	$ 128
Derivatives	(12)	(306)	(180)	(127)
Amounts related to interest settlements on derivatives	14	34	38	87
Total net interest income recognized on fair value hedges	14	30	36	88
Interest Expense
Derivative Instruments, Gain (Loss) [Line Items]
Hedged items	(3)	(8)	(7)	(8)
Derivatives	3	8	7	8
Amounts related to interest settlements on derivatives	(3)	(4)	(8)	(11)
Total net interest income recognized on fair value hedges	$ (3)	$ (4)	$ (8)	$ (11)