Business Segment Information - Nonoperating Income (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Noninterest income:
Fixed income	$ 42	$ 40	$ 91	$ 92
Deposit transactions and cash management	41	44	81	88
Brokerage, management fees and commissions	26	25	52	49
Card and digital banking fees	19	20	37	38
Other service charges and fees	14	14	26	27
Trust services and investment management	13	12	25	24
Mortgage banking income	10	10	18	19
Securities gains (losses), net	0	1	0	1
Other income	24	20	40	43
Total noninterest income	189	186	370	381
Underwriting, portfolio advisory, and other noninterest income
Noninterest income:
Revenue from contract with customer	9	9	18	20
Commercial, Consumer & Wealth
Noninterest income:
Fixed income	0	0	0	0
Deposit transactions and cash management	39	41	76	82
Brokerage, management fees and commissions	26	25	52	49
Card and digital banking fees	16	17	32	33
Other service charges and fees	13	12	25	24
Trust services and investment management	12	12	24	23
Mortgage banking income	0	0	0	0
Securities gains (losses), net		0		0
Other income	7	8	14	14
Total noninterest income	113	115	223	225
Wholesale
Noninterest income:
Fixed income	42	40	91	92
Deposit transactions and cash management	0	1	1	2
Brokerage, management fees and commissions	0	0	0	0
Card and digital banking fees	0	0	0	0
Other service charges and fees	1	2	1	2
Trust services and investment management	0	0	0	0
Mortgage banking income	10	10	18	18
Securities gains (losses), net		0		0
Other income	0	0	2	1
Total noninterest income	53	53	113	115
Corporate
Noninterest income:
Fixed income	0	0	0	0
Deposit transactions and cash management	2	2	4	4
Brokerage, management fees and commissions	0	0	0	0
Card and digital banking fees	3	3	5	5
Other service charges and fees	0	0	0	1
Trust services and investment management	1	0	1	1
Mortgage banking income	0	0	0	1
Securities gains (losses), net		1		1
Other income	17	12	24	28
Total noninterest income	$ 23	$ 18	$ 34	$ 41