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	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Interest Rate Contract | Customer Contracts | Corporate Banking Revenue
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	$ 9	$ 8	$ 14	$ 14
Interest Rate Contract | Customer Contracts | Other Noninterest Expense
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	(2)		(3)
Interest Rate Contract | Fair Value Adjustments on Hedges and Derivative Contracts | Other Noninterest Expense
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	3		4	3
Interest Rate Contract | Interest Rate Lock Commitments | Mortgage Banking Revenue
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	(58)	125	(2)	175
Commodity Contract | Customer Contracts | Corporate Banking Revenue
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	2	3	4	5
Commodity Contract | Fair Value Adjustments on Hedges and Derivative Contracts | Other Noninterest Expense
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	(1)	1	(1)
Foreign Exchange Contract | Customer Contracts | Corporate Banking Revenue
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	20	19	38	34
Foreign Exchange Contract | Fair Value Adjustments on Hedges and Derivative Contracts | Other Noninterest Expense
Derivative Instruments, Gain (Loss)
Net gains (losses) recorded in earnings	$ (1)	$ (1)	$ (1)	$ 1