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, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ 1,380	$ 1,105	$ 1,337	$ 1,061
Provision	152	38	240	115
Charge-offs	(76)	(59)	(136)	(110)
Recoveries	24	15	39	33
Ending balance	1,480	1,099	1,480	1,099
Total ALLL, including discontinued operations, beginning balance	1,399	1,132	1,358	1,089
Total provision, including discontinued operations	152	35	239	113
Total charge-offs, including discontinued operations	(78)	(60)	(139)	(113)
Total recoveries, including discontinued operations	25	16	40	34
Total ALLL — including discontinued operations	1,498	1,123	1,498	1,123
Provision (credit) for losses on lending-related commitments	15	7	66	13
Total commercial loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	884	717	864	688
Provision	136	23	186	76
Charge-offs	(52)	(42)	(91)	(78)
Recoveries	18	11	27	23
Ending balance	986	709	986	709
Total consumer loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	496	388	473	373
Provision	16	15	54	39
Charge-offs	(24)	(17)	(45)	(32)
Recoveries	6	4	12	10
Ending balance	494	390	494	390
Commercial and Industrial | Total commercial loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	605	489	601	445
Provision	21	45	52	108
Charge-offs	(42)	(39)	(77)	(69)
Recoveries	15	8	23	19
Ending balance	599	503	599	503
Commercial mortgage | Total commercial loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	218	172	203	182
Provision	105	(14)	125	(21)
Charge-offs	(9)	(3)	(14)	(7)
Recoveries	1	1	1	2
Ending balance	315	156	315	156
Construction | Total commercial loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	28	25	28	29
Provision	11	(5)	11	(9)
Charge-offs	0	0	0	0
Recoveries	0	1	0	1
Ending balance	39	21	39	21
Total commercial real estate loans | Total commercial loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	246	197	231	211
Provision	116	(19)	136	(30)
Charge-offs	(9)	(3)	(14)	(7)
Recoveries	1	2	1	3
Ending balance	354	177	354	177
Commercial lease financing | Total commercial loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	33	31	32	32
Provision	(1)	(3)	(2)	(2)
Charge-offs	(1)	0	0	(2)
Recoveries	2	1	3	1
Ending balance	33	29	33	29
Real estate — residential mortgage | Total consumer loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	212	108	196	95
Provision	(12)	11	3	23
Charge-offs	(1)		(1)
Recoveries	1	1	2	1
Ending balance	200	122	200	122
Real estate — residential mortgage | Total consumer loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs		2		3
Home equity loans | Total consumer loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	96	104	98	110
Provision	1	(10)	(1)	(16)
Charge-offs	(2)	0	(3)	(1)
Recoveries	1	1	2	2
Ending balance	96	95	96	95
Consumer direct loans | Total consumer loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	116	111	111	105
Provision	18	10	32	21
Charge-offs	(11)	(10)	(22)	(17)
Recoveries	2	1	4	3
Ending balance	125	112	125	112
Credit cards | Total consumer loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	71	63	66	61
Provision	8	3	21	10
Charge-offs	(9)	(8)	(18)	(15)
Recoveries	2	1	3	3
Ending balance	72	59	72	59
Consumer indirect loans | Total consumer loans
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	1	2	2	2
Provision	1	1	(1)	1
Charge-offs	(1)	(1)	(1)	(2)
Recoveries	0	0	1	1
Ending balance	1	2	1	2
Discontinued operations
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	19	27	21	28
Provision	0	(3)	(1)	(2)
Charge-offs	(2)	(1)	(3)	(3)
Recoveries	1	1	1	1
Ending balance	$ 18	$ 24	$ 18	$ 24