BUSINESS OPERATING SEGMENTS - Schedule of Business Operating Segments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Net interest income	$ 5,633	$ 6,241	$ 6,012
Noninterest income	2,176	1,983	2,009
Total revenue	7,809	8,224	8,021
Direct expenses	5,234	5,507	4,892
Indirect expenses	0	0	0
Total noninterest expense	5,234	5,507	4,892
Profit (loss) before provision for credit losses	2,575	2,717	3,129
Provision (benefit) for credit losses	687	687	474
Income before income tax expense	1,888	2,030	2,655
Income tax expense	379	422	582
NET INCOME	1,509	1,608	2,073
Total average assets	219,024	222,221	215,061
Operating Segments
Segment Reporting Information [Line Items]
Noninterest income	2,176	1,983	2,009
Operating Segments | Consumer Banking
Segment Reporting Information [Line Items]
Net interest income	4,565	4,187	3,649
Noninterest income	1,131	1,067	1,063
Total revenue	5,696	5,254	4,712
Direct expenses	2,325	2,244	2,103
Indirect expenses	1,353	1,298	1,152
Total noninterest expense	3,678	3,542	3,255
Profit (loss) before provision for credit losses	2,018	1,712	1,457
Provision (benefit) for credit losses	331	280	174
Income before income tax expense	1,687	1,432	1,283
Income tax expense	434	373	328
NET INCOME	1,253	1,059	955
Total average assets	75,037	72,693	68,027
Depreciation and amortization	113	106	97
Operating Segments | Commercial Banking
Segment Reporting Information [Line Items]
Net interest income	1,950	2,292	2,103
Noninterest income	908	784	845
Total revenue	2,858	3,076	2,948
Direct expenses	835	857	820
Indirect expenses	406	438	403
Total noninterest expense	1,241	1,295	1,223
Profit (loss) before provision for credit losses	1,617	1,781	1,725
Provision (benefit) for credit losses	353	250	46
Income before income tax expense	1,264	1,531	1,679
Income tax expense	291	378	375
NET INCOME	973	1,153	1,304
Total average assets	68,478	76,028	74,919
Depreciation and amortization	26	30	27
Operating Segments | Non-Core
Segment Reporting Information [Line Items]
Net interest income	(117)	(129)	378
Noninterest income	0	0	0
Total revenue	(117)	(129)	378
Direct expenses	4	13	23
Indirect expenses	94	110	113
Total noninterest expense	98	123	136
Profit (loss) before provision for credit losses	(215)	(252)	242
Provision (benefit) for credit losses	61	78	52
Income before income tax expense	(276)	(330)	190
Income tax expense	(70)	(86)	48
NET INCOME	(206)	(244)	142
Total average assets	8,942	13,745	18,121
Other
Segment Reporting Information [Line Items]
Net interest income	(765)	(109)	(118)
Noninterest income	137	132	101
Total revenue	(628)	23	(17)
Direct expenses	2,070	2,393	1,946
Indirect expenses	(1,853)	(1,846)	(1,668)
Total noninterest expense	217	547	278
Profit (loss) before provision for credit losses	(845)	(524)	(295)
Provision (benefit) for credit losses	(58)	79	202
Income before income tax expense	(787)	(603)	(497)
Income tax expense	(276)	(243)	(169)
NET INCOME	(511)	(360)	(328)
Total average assets	66,567	59,755	53,994
Depreciation and amortization	$ 312	$ 291	$ 274