DERIVATIVES - Schedule of Fair Value Hedges (Details) - Hedge of interest rate risk - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Interest Income, Investment Securities
Derivative Instruments, Gain (Loss) [Line Items]
Hedged Item	$ 161	$ (142)	$ 50
Derivative	(163)	147	(48)
Amounts related to interest settlements on derivatives	45	107	10
Total net interest income recognized on fair value hedges	43	112	12
Interest Expense Long-Term Borrowed Funds
Derivative Instruments, Gain (Loss) [Line Items]
Hedged Item	(8)	(8)	(10)
Derivative	8	8	10
Amounts related to interest settlements on derivatives	(9)	(14)	(16)
Total net interest income recognized on fair value hedges	$ (9)	$ (14)	$ (16)