Business Segments - Results of Operations and Average Assets by Segment (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information
Net interest income (FTE)		$ 5,654	$ 5,852	$ 5,625
Provision for credit losses		530	515	563
Net interest income after provision for (benefit from) credit losses		5,124	5,337	5,062
Noninterest income:
Wealth and asset management revenue		647	581	570
Commercial payments revenue		608	564	568
Consumer banking revenue		555	546	542
Capital markets fees		424	422	387
Commercial banking revenue		377	409	419
Mortgage banking net revenue		211	250	215
Other noninterest income		12	91	149
Securities gains (losses), net		15	18	(84)
Total noninterest income		2,849	2,881	2,766
Noninterest Expense
Compensation and benefits	[1]	2,763	2,694	2,554
Technology and communications	[1]	474	464	416
Net occupancy expense	[1]	339	331	307
Equipment expense	[1]	153	148	145
Loan and lease expense	[1]	132	133	167
Marketing expense	[1]	115	126	118
Card and processing expense	[1]	84	84	80
Other noninterest expense	[1]	973	1,225	932
Total noninterest expense	[1]	5,033	5,205	4,719
Income (loss) before income taxes (FTE)		2,940	3,013	3,109
Average assets		212,806	208,426	206,929
Impairment losses on bank premises		1	2	9
Impairment losses and termination charges		1	2	2
Operating Segments | Commercial Banking
Segment Reporting Information
Net interest income (FTE)		2,647	3,828	2,552
Provision for credit losses		304	12	33
Net interest income after provision for (benefit from) credit losses		2,343	3,816	2,519
Noninterest income:
Wealth and asset management revenue		3	2	3
Commercial payments revenue		529	473	468
Consumer banking revenue		0	0	0
Capital markets fees		421	419	387
Commercial banking revenue		373	406	417
Mortgage banking net revenue		0	0	0
Other noninterest income		53	65	98
Securities gains (losses), net		1	(9)	(33)
Total noninterest income		1,380	1,356	1,340
Noninterest Expense
Compensation and benefits		656	654	639
Technology and communications		14	14	11
Net occupancy expense		36	41	40
Equipment expense		28	29	27
Loan and lease expense		31	30	27
Marketing expense		3	3	5
Card and processing expense		9	11	11
Other noninterest expense		1,117	1,221	1,063
Total noninterest expense		1,894	2,003	1,823
Income (loss) before income taxes (FTE)		1,829	3,169	2,036
Average assets		77,177	83,078	82,239
FTE adjustments		15	16	10
Impairment losses of operating lease equipment				2
Operating Segments | Consumer and Small Business Banking
Segment Reporting Information
Net interest income (FTE)		4,169	5,207	3,131
Provision for credit losses		322	303	139
Net interest income after provision for (benefit from) credit losses		3,847	4,904	2,992
Noninterest income:
Wealth and asset management revenue		247	216	204
Commercial payments revenue		76	85	89
Consumer banking revenue		551	544	538
Capital markets fees		2	2	2
Commercial banking revenue		4	2	1
Mortgage banking net revenue		210	250	214
Other noninterest income		4	6	7
Securities gains (losses), net		0	0	(2)
Total noninterest income		1,094	1,105	1,053
Noninterest Expense
Compensation and benefits		882	878	828
Technology and communications		30	27	22
Net occupancy expense		212	209	196
Equipment expense		51	44	38
Loan and lease expense		80	86	107
Marketing expense		68	70	58
Card and processing expense		75	76	72
Other noninterest expense		1,074	1,125	1,068
Total noninterest expense		2,472	2,515	2,389
Income (loss) before income taxes (FTE)		2,469	3,494	1,656
Average assets		51,627	50,974	49,823
Impairment losses on bank premises			1	6
Operating Segments | Wealth and Asset Management
Segment Reporting Information
Net interest income (FTE)		210	360	262
Provision for credit losses		0	1	0
Net interest income after provision for (benefit from) credit losses		210	359	262
Noninterest income:
Wealth and asset management revenue		397	363	363
Commercial payments revenue		1	1	1
Consumer banking revenue		2	2	2
Capital markets fees		2	1	0
Commercial banking revenue		0	0	1
Mortgage banking net revenue		1	0	1
Other noninterest income		1	2	0
Securities gains (losses), net		0	0	0
Total noninterest income		404	369	368
Noninterest Expense
Compensation and benefits		222	220	218
Technology and communications		1	1	1
Net occupancy expense		12	12	13
Equipment expense		0	0	0
Loan and lease expense		1	1	1
Marketing expense		1	1	1
Card and processing expense		1	1	1
Other noninterest expense		149	139	144
Total noninterest expense		387	375	379
Income (loss) before income taxes (FTE)		227	353	251
Average assets		4,390	4,678	4,763
Corporate Corporate and Other
Segment Reporting Information
Net interest income (FTE)		(1,372)	(3,543)	(320)
Provision for credit losses		(96)	199	391
Net interest income after provision for (benefit from) credit losses		(1,276)	(3,742)	(711)
Noninterest income:
Wealth and asset management revenue		0	0	0
Commercial payments revenue		2	5	10
Consumer banking revenue		2	0	2
Capital markets fees		(1)	0	(2)
Commercial banking revenue		0	1	0
Mortgage banking net revenue		0	0	0
Other noninterest income		(46)	18	44
Securities gains (losses), net		14	27	(49)
Total noninterest income		(29)	51	5
Noninterest Expense
Compensation and benefits		1,003	942	869
Technology and communications		429	422	382
Net occupancy expense		79	69	58
Equipment expense		74	75	80
Loan and lease expense		20	16	32
Marketing expense		43	52	54
Card and processing expense		(1)	(4)	(4)
Other noninterest expense		(1,367)	(1,260)	(1,343)
Total noninterest expense		280	312	128
Income (loss) before income taxes (FTE)		(1,585)	(4,003)	(834)
Average assets		79,612	69,696	70,104
FTE adjustments		$ 9	9	6
Impairment losses on bank premises			$ 1	$ 3

[1] During the fourth quarter of 2024, certain noninterest income and noninterest expense line items were reclassified to better align disclosures to business activities. These reclassifications were retrospectively applied to all prior periods presented. Total noninterest income and noninterest expense did not change as a result of these reclassifications. Refer to Note 1 for additional information.