Net Gains (Losses) Recorded in the Consolidated Statements of Income Relating to Free-Standing Derivative Instruments Used For Customer Accommodation (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Interest Rate Contract | Customer Contracts | Corporate Banking Revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	$ 28	$ 26	$ 21
Interest Rate Contract | Allowance for Loan and Lease Losses (Member) | Other Noninterest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	(13)	(22)	(33)
Interest Rate Contract | Fair Value Adjustments on Hedges and Derivative Contracts | Other Noninterest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	13	(1)	(7)
Interest Rate Contract | Interest Rate Lock Commitments | Mortgage Banking Revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	206	187	129
Commodity Contract | Customer Contracts | Corporate Banking Revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	8	8	6
Commodity Contract | Fair Value Adjustments on Hedges and Derivative Contracts | Other Noninterest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings			2
Foreign Exchange Contract | Customer Contracts | Corporate Banking Revenue [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	47	63	76
Foreign Exchange Contract | Fair Value Adjustments on Hedges and Derivative Contracts | Other Noninterest Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	$ 1	$ (1)	$ 2