Business Segments - Results of Operations and Average Assets by Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Segment Reporting Information
Net interest income (FTE)	$ 1,442	$ 1,390
Provision for credit losses	174	94
Net interest income after provision for (benefit from) credit losses	1,268	1,296
Noninterest Income
Wealth and asset management revenue	172	161
Commercial payments revenue	153	145
Consumer banking revenue	137	135
Capital markets fees	90	97
Commercial banking revenue	80	85
Mortgage banking net revenue	57	54
Other noninterest income	14	23
Securities (losses) gains, net	(9)	10
Total noninterest income	694	710
Noninterest Expense
Compensation and benefits	750	753
Technology and communications	123	117
Net occupancy expense	87	87
Equipment expense	42	37
Loan and lease expense	30	29
Marketing expense	28	32
Card and processing expense	21	20
Other noninterest expense	223	267
Total noninterest expense	1,304	1,342
Income (loss) before income taxes (FTE)	658	664
Average assets	210,558	213,203
Operating Segments | Commercial Banking
Segment Reporting Information
Net interest income (FTE)	552	663
Provision for credit losses	80	71
Net interest income after provision for (benefit from) credit losses	472	592
Noninterest Income
Wealth and asset management revenue	0	1
Commercial payments revenue	133	125
Consumer banking revenue	0	0
Capital markets fees	90	96
Commercial banking revenue	79	85
Mortgage banking net revenue	0	0
Other noninterest income	6	17
Securities (losses) gains, net	(7)	1
Total noninterest income	301	325
Noninterest Expense
Compensation and benefits	178	186
Technology and communications	3	4
Net occupancy expense	9	9
Equipment expense	8	7
Loan and lease expense	7	6
Marketing expense	1	1
Card and processing expense	3	2
Other noninterest expense	302	275
Total noninterest expense	511	490
Income (loss) before income taxes (FTE)	262	427
Average assets	77,940	77,415
FTE adjustments	3	4
Operating Segments | Consumer and Small Business Banking
Segment Reporting Information
Net interest income (FTE)	975	1,152
Provision for credit losses	84	84
Net interest income after provision for (benefit from) credit losses	891	1,068
Noninterest Income
Wealth and asset management revenue	66	59
Commercial payments revenue	20	20
Consumer banking revenue	135	132
Capital markets fees	0	1
Commercial banking revenue	1	0
Mortgage banking net revenue	57	54
Other noninterest income	2	1
Securities (losses) gains, net	0	0
Total noninterest income	281	267
Noninterest Expense
Compensation and benefits	236	237
Technology and communications	7	7
Net occupancy expense	54	54
Equipment expense	16	13
Loan and lease expense	18	17
Marketing expense	19	22
Card and processing expense	17	19
Other noninterest expense	283	281
Total noninterest expense	650	650
Income (loss) before income taxes (FTE)	522	685
Average assets	54,406	51,363
Operating Segments | Wealth and Asset Management
Segment Reporting Information
Net interest income (FTE)	49	59
Provision for credit losses	0	0
Net interest income after provision for (benefit from) credit losses	49	59
Noninterest Income
Wealth and asset management revenue	106	101
Commercial payments revenue	0	0
Consumer banking revenue	1	1
Capital markets fees	1	0
Commercial banking revenue	0	0
Mortgage banking net revenue	0	0
Other noninterest income	1	0
Securities (losses) gains, net	0	0
Total noninterest income	109	102
Noninterest Expense
Compensation and benefits	62	62
Technology and communications	0	0
Net occupancy expense	3	3
Equipment expense	0	0
Loan and lease expense	0	0
Marketing expense	0	0
Card and processing expense	1	0
Other noninterest expense	40	38
Total noninterest expense	106	103
Income (loss) before income taxes (FTE)	52	58
Average assets	4,657	4,413
General Corporate and Other
Segment Reporting Information
Net interest income (FTE)	(134)	(484)
Provision for credit losses	10	(61)
Net interest income after provision for (benefit from) credit losses	(144)	(423)
Noninterest Income
Wealth and asset management revenue	0	0
Commercial payments revenue	0	0
Consumer banking revenue	1	2
Capital markets fees	(1)	0
Commercial banking revenue	0	0
Mortgage banking net revenue	0	0
Other noninterest income	5	5
Securities (losses) gains, net	(2)	9
Total noninterest income	3	16
Noninterest Expense
Compensation and benefits	274	268
Technology and communications	113	106
Net occupancy expense	21	21
Equipment expense	18	17
Loan and lease expense	5	6
Marketing expense	8	9
Card and processing expense	0	(1)
Other noninterest expense	(402)	(327)
Total noninterest expense	37	99
Income (loss) before income taxes (FTE)	(178)	(506)
Average assets	73,555	80,012
FTE adjustments	$ 2	$ 2