Business Segment Information - Nonoperating Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Noninterest income:
Fixed income	$ 57	$ 47	$ 149	$ 138
Deposit transactions and cash management	43	45	125	134
Brokerage, management fees and commissions	26	27	77	76
Card and digital banking fees	19	19	55	58
Other service charges and fees	14	13	40	40
Trust services and investment management	13	12	38	36
Mortgage banking income	15	9	33	28
Securities gains (losses), net	0	1	1	2
Other income	28	27	67	69
Total noninterest income	215	200	585	581
Underwriting, portfolio advisory, and other noninterest income
Noninterest income:
Revenue from contract with customer	14	11	32	31
Commercial, Consumer & Wealth
Noninterest income:
Fixed income	0	0	0	0
Deposit transactions and cash management	40	42	116	124
Brokerage, management fees and commissions	26	27	77	76
Card and digital banking fees	16	16	48	50
Other service charges and fees	14	13	38	37
Trust services and investment management	13	12	37	35
Mortgage banking income	0	0	1	1
Securities gains (losses), net		0	0	0
Other income	8	9	23	22
Total noninterest income	117	119	340	345
Wholesale
Noninterest income:
Fixed income	57	47	149	138
Deposit transactions and cash management	1	1	2	3
Brokerage, management fees and commissions	0	0	0	0
Card and digital banking fees	0	0	0	0
Other service charges and fees	0	0	2	3
Trust services and investment management	0	0	0	0
Mortgage banking income	15	8	32	26
Securities gains (losses), net		0	0	0
Other income	0	0	2	2
Total noninterest income	73	56	187	172
Corporate
Noninterest income:
Fixed income	0	0	0	0
Deposit transactions and cash management	2	2	7	7
Brokerage, management fees and commissions	0	0	0	0
Card and digital banking fees	3	3	7	8
Other service charges and fees	0	0	0	0
Trust services and investment management	0	0	1	1
Mortgage banking income	0	1	0	1
Securities gains (losses), net		1	1	2
Other income	20	18	42	45
Total noninterest income	$ 25	$ 25	$ 58	$ 64