Business Segment Information - Amounts of Consolidated Revenue, Expense, Tax and Assets by Segment (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2025	Jun. 30, 2024
Disaggregation of Revenue [Line Items]
Interest income	$ 1,044		$ 1,093		$ 2,058	$ 2,165
Interest expense	403		464		786	912
Funds transfer pricing	0		0		0	0
Net interest income (expense)	641		629		1,272	1,253
Noninterest income	189		186		370	381
Total revenues	830		815		1,642	1,634
Noninterest expense	491		500		978	1,015
Pre-provision net revenue	339		315		664	619
Provision for credit losses	30		55		70	105
Income (loss) before income taxes	309		260		594	514
Income tax expense (benefit)	64		56		127	113
Net income (loss)	245	$ 222	204	$ 197	467	401
Average assets	81,958		81,721		81,464	81,482
Depreciation and amortization	20		20		41	51
Expenditures for long-lived assets	7		12		16	21
Commercial, Consumer & Wealth
Disaggregation of Revenue [Line Items]
Interest income	826		894		1,639	1,776
Interest expense	295		352		585	703
Funds transfer pricing	102		95		204	190
Net interest income (expense)	633		637		1,258	1,263
Noninterest income	113		115		223	225
Total revenues	746		752		1,481	1,488
Noninterest expense	354		357		698	704
Pre-provision net revenue	392		395		783	784
Provision for credit losses	13		56		51	100
Income (loss) before income taxes	379		339		732	684
Income tax expense (benefit)	90		80		174	161
Net income (loss)	289		259		558	523
Average assets	58,737		59,684		58,727	59,516
Depreciation and amortization	7		3		17	18
Expenditures for long-lived assets	5		8		10	11
Wholesale
Disaggregation of Revenue [Line Items]
Interest income	140		131		264	246
Interest expense	26		34		55	65
Funds transfer pricing	(56)		(50)		(103)	(93)
Net interest income (expense)	58		47		106	88
Noninterest income	53		53		113	115
Total revenues	111		100		219	203
Noninterest expense	76		73		151	148
Pre-provision net revenue	35		27		68	55
Provision for credit losses	6		1		9	8
Income (loss) before income taxes	29		26		59	47
Income tax expense (benefit)	7		6		14	11
Net income (loss)	22		20		45	36
Average assets	9,308		8,021		8,903	7,584
Depreciation and amortization	2		2		4	4
Expenditures for long-lived assets	0		0		1	0
Corporate
Disaggregation of Revenue [Line Items]
Interest income	78		68		155	143
Interest expense	82		78		146	144
Funds transfer pricing	(46)		(45)		(101)	(97)
Net interest income (expense)	(50)		(55)		(92)	(98)
Noninterest income	23		18		34	41
Total revenues	(27)		(37)		(58)	(57)
Noninterest expense	61		70		129	163
Pre-provision net revenue	(88)		(107)		(187)	(220)
Provision for credit losses	11		(2)		10	(3)
Income (loss) before income taxes	(99)		(105)		(197)	(217)
Income tax expense (benefit)	(33)		(30)		(61)	(59)
Net income (loss)	(66)		(75)		(136)	(158)
Average assets	13,913		14,016		13,834	14,382
Depreciation and amortization	11		15		20	29
Expenditures for long-lived assets	2		4		5	10
Deferred compensation expense credit	4				4
Restructuring costs			3			9
Special assessment fee (credit)	$ (1)		$ 2			$ 12
Corporate | Visa Class B Shares
Disaggregation of Revenue [Line Items]
Derivative valuation adjustment prior sales of visa class b shares					$ 5