Business Segment Information - Noninterest Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Noninterest income:
Fixed income	$ 53	$ 49
Deposit transactions and cash management	43	40
Brokerage, management fees and commissions	29	26
Card and digital banking fees	18	18
Other service charges and fees	16	12
Trust services and investment management	13	12
Mortgage banking income	9	8
Securities gains (losses), net	(1)	0
Other income	15	16
Total noninterest income	195	181
Underwriting, portfolio advisory, and other noninterest income
Noninterest income:
Revenue from contract with customer	11	9
Commercial, Consumer & Wealth
Noninterest income:
Fixed income	0	0
Deposit transactions and cash management	40	37
Brokerage, management fees and commissions	29	26
Card and digital banking fees	15	16
Other service charges and fees	16	12
Trust services and investment management	13	12
Mortgage banking income	0	0
Securities gains (losses), net	0
Other income	6	7
Total noninterest income	119	110
Wholesale
Noninterest income:
Fixed income	53	49
Deposit transactions and cash management	1	1
Brokerage, management fees and commissions	0	0
Card and digital banking fees	0	0
Other service charges and fees	0	0
Trust services and investment management	0	0
Mortgage banking income	9	8
Securities gains (losses), net	0
Other income	1	1
Total noninterest income	64	59
Corporate
Noninterest income:
Fixed income	0	0
Deposit transactions and cash management	2	2
Brokerage, management fees and commissions	0	0
Card and digital banking fees	3	2
Other service charges and fees	0	0
Trust services and investment management	0	0
Mortgage banking income	0	0
Securities gains (losses), net	(1)
Other income	8	8
Total noninterest income	$ 12	$ 12