Stockholders' Equity - Reclassification Out of AOCI (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
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other-Non-interest expense	$ (490)	$ (708)	$ (1,031)	$ (1,144)
Other-Non-interest income	69	120	80	318
Income tax provision	581	43	1,075	396
Net income	1,117	93	2,183	1,496
Total reclassifications	1,100	92	2,148	1,488
Reclassification Out of AOCI [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Net income	1		2
Total reclassifications	12		18
Reclassification Out of AOCI [Member] | Securities Available for Sale [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other-Non-interest income	1		3
Income tax provision	0		1
Reclassification Out of AOCI [Member] | Cash Flow Hedges [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before tax	16		28
Income tax provision	6		11
Net income	10		17
Reclassification Out of AOCI [Member] | Cash Flow Hedges [Member] | Interest Rate Contracts [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other-Non-interest income	22		42
Reclassification Out of AOCI [Member] | Cash Flow Hedges [Member] | Foreign Exchange Contracts [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Other-Non-interest expense	(6)		(14)
Reclassification Out of AOCI [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Salaries and associate benefits	2		(1)
Income tax provision	1		0
Net income	$ 1		$ (1)