Derivative Financial Instruments - Net Gains (Losses) Recorded in the Consolidated Statements of Income Relating to Free-Standing Derivative Instruments Used For Customer Accommodation (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	$ 45	$ (75)	$ (17)	$ (110)
Interest rate contracts | Contract revenue | Commercial banking revenue
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	9	5	20	26
Interest rate contracts | Credit portion of fair value adjustment | Other noninterest expense
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	(4)	4	0	2
Interest rate contracts | Interest rate lock commitments | Mortgage banking net revenue
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	17	7	37	33
Commodity contracts | Contract revenue | Commercial banking revenue
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	3	9	11	30
Commodity contracts | Credit portion of fair value adjustment | Other noninterest expense
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	0	1	1	0
Foreign exchange contracts | Other noninterest income
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	(1)	5	5	1
Foreign exchange contracts | Contract revenue | Commercial banking revenue
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	18	24	57	67
Foreign exchange contracts | Contract revenue | Other noninterest income
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	(16)	7	(13)	0
Foreign exchange contracts | Credit portion of fair value adjustment | Other noninterest expense
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	$ 0	$ 1	$ 0	$ 3