Net Gains (Losses) Recorded in the Consolidated Statements of Income Relating to Free-Standing Derivative Instruments Used For Customer Accommodation (Detail) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Interest Rate Contract | Customer Contracts | Corporate Banking Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	$ 7	$ 7	$ 22	$ 18
Interest Rate Contract | Allowance for Loan and Lease Losses (Member) | Noninterest Expense, Other
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings		(6)	(12)	(13)
Interest Rate Contract | Fair Value Adjustments on Hedges and Derivative Contracts | Noninterest Expense, Other
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings		(3)	10	(11)
Interest Rate Contract | Interest Rate Lock Commitments | Mortgage Banking Revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	100	101	156	210
Commodity Contract | Customer Contracts | Corporate Banking Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	3	2	6	6
Commodity Contract | Fair Value Adjustments on Hedges and Derivative Contracts | Noninterest Expense, Other
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	(1)			(1)
Foreign Exchange Contract | Customer Contracts | Corporate Banking Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	17	14	48	46
Foreign Exchange Contract | Fair Value Adjustments on Hedges and Derivative Contracts | Noninterest Expense, Other
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	$ (3)	$ 1	$ (2)	$ 1