Asset Quality - Schedule of Changes in Allowance for Loan and Lease Losses by Loan Category (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 1,542	$ 1,380	$ 1,508	$ 1,337
Provision	96	152	211	240
Charge-offs	(131)	(76)	(228)	(136)
Recoveries	40	24	56	39
Ending balance	1,547	1,480	1,547	1,480
Total ALLL, including discontinued operations, beginning balance	1,557	1,399	1,524	1,358
Total provision, including discontinued operations	95	152	210	239
Total charge-offs, including discontinued operations	(132)	(78)	(230)	(139)
Total recoveries, including discontinued operations	41	25	57	40
Total ALLL, including discontinued operations, ending balance	1,561	1,498	1,561	1,498
Provision (credit) for losses on lending-related commitments	4	15	(10)	66
Total commercial loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1,131	884	1,060	864
Provision	96	136	224	186
Charge-offs	(102)	(52)	(169)	(91)
Recoveries	35	18	45	27
Ending balance	1,160	986	1,160	986
Total consumer loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	411	496	448	473
Provision	0	16	(13)	54
Charge-offs	(29)	(24)	(59)	(45)
Recoveries	5	6	11	12
Ending balance	387	494	387	494
Commercial and Industrial | Total commercial loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	653	605	556	601
Provision	84	21	235	52
Charge-offs	(86)	(42)	(148)	(77)
Recoveries	31	15	39	23
Ending balance	682	599	682	599
Total commercial real estate loans | Total commercial loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	450	246	471	231
Provision	8	116	(8)	136
Charge-offs	(10)	(9)	(15)	(14)
Recoveries	1	1	1	1
Ending balance	449	354	449	354
Real estate — commercial mortgage | Total commercial loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	389	218	419	203
Provision	3	105	(22)	125
Charge-offs	(10)	(9)	(15)	(14)
Recoveries	1	1	1	1
Ending balance	383	315	383	315
Real estate — construction | Total commercial loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	61	28	52	28
Provision	5	11	14	11
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Ending balance	66	39	66	39
Commercial lease financing | Total commercial loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	28	33	33	32
Provision	4	(1)	(3)	(2)
Charge-offs	(6)	(1)	(6)	0
Recoveries	3	2	5	3
Ending balance	29	33	29	33
Real estate — residential mortgage | Total consumer loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	121	212	162	196
Provision	(6)	(12)	(48)	3
Charge-offs	(1)	(1)	(2)	(1)
Recoveries	1	1	3	2
Ending balance	115	200	115	200
Home equity loans | Total consumer loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	79	96	86	98
Provision	(8)	1	(15)	(1)
Charge-offs	0	(2)	(1)	(3)
Recoveries	0	1	1	2
Ending balance	71	96	71	96
Other consumer loans | Total consumer loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	133	117	122	113
Provision	9	19	34	31
Charge-offs	(16)	(12)	(32)	(23)
Recoveries	2	2	4	5
Ending balance	128	126	128	126
Credit cards | Total consumer loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	78	71	78	66
Provision	5	8	16	21
Charge-offs	(12)	(9)	(24)	(18)
Recoveries	2	2	3	3
Ending balance	73	72	73	72
Discontinued operations
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	15	19	16	21
Provision	(1)	0	(1)	(1)
Charge-offs	(1)	(2)	(2)	(3)
Recoveries	1	1	1	1
Ending balance	$ 14	$ 18	$ 14	$ 18