Net Gains (Losses) Recorded in the Consolidated Statements of Income Relating to Free-Standing Derivative Instruments Used For Risk Management (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 | Forward Contracts | Mortgage Banking Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	$ (57)	$ 18	$ (136)	$ (63)
Interest Rate Contract | Interest Rate Swap | Other Noninterest Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	2		6	2
Interest Rate Contract | Mortgage Servicing Rights | Mortgage Banking Revenue
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	235	129	337	283
Foreign Exchange Contract | Other Noninterest Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings		(1)		1
Equity Contract | Warrants | Other Noninterest Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	(3)	(6)	22	1
Equity Contract | Put Option | Other Noninterest Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	6	1	8	1
Equity Contract | Swap | Other Noninterest Income [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net gains (losses) recorded in earnings	$ (17)	$ (5)	$ (30)	$ (14)