VARIABLE INTEREST ENTITIES - Schedule of Affordable Housing Tax Credit Investments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Variable Interest Entity
Income tax expense	$ (135)	$ (88)	$ (348)	$ (272)
Noninterest income	630	532	1,774	1,602
Net income	494	382	1,303	1,108
Variable Interest Entity, Not Primary Beneficiary | Net Income (Loss) Attributable To Parent, Net Benefit
Variable Interest Entity
Net income	23	30	73	77
Variable Interest Entity, Not Primary Beneficiary | Net benefit (expense) included in Income tax expense
Variable Interest Entity
Income tax expense	25	32	78	82
Variable Interest Entity, Not Primary Beneficiary | Tax credits recognized
Variable Interest Entity
Income tax expense	99	99	309	290
Variable Interest Entity, Not Primary Beneficiary | Other tax benefits recognized
Variable Interest Entity
Income tax expense	24	21	73	68
Variable Interest Entity, Not Primary Beneficiary | Amortization
Variable Interest Entity
Income tax expense	(98)	(88)	(304)	(276)
Variable Interest Entity, Not Primary Beneficiary | Net benefit (expense) included in Noninterest income
Variable Interest Entity
Noninterest income	(2)	(2)	(5)	(5)
Variable Interest Entity, Not Primary Beneficiary | Other income
Variable Interest Entity
Noninterest income	1	1	5	4
Variable Interest Entity, Not Primary Beneficiary | Allocated income (loss) on investments
Variable Interest Entity
Noninterest income	$ (3)	$ (3)	$ (10)	$ (9)