Accumulated Other Comprehensive Income (Loss) - Summary of Changes in Accumulated Other Comprehensive Income (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		Dec. 31, 2012
Unrealized gains (losses) on cash flow hedging instruments:
Balance at beginning of period	$ (190)		$ (439)		$ (358)		$ (494)
Net gains (losses) arising during period, net of tax of $19 million and $(5) million for the three months ended, $39 million and $24 million for the six month period ended	36		(9)		72		41
Reclassification adjustment for losses realized in net income, net of tax of $1 million and $2 million for the three months ended, and $74 million and $5 million for the six month period ended	2	[1]	4	[1]	134	[1]	9	[1]
Total other comprehensive income (loss) for period	38		(5)		206		50
Balance at end of period	(152)		(444)		(152)		(444)
Unrealized gains (losses) on securities available-for-sale, not other-than temporarily impaired:
Balance at beginning of period	0		93		115		102
Reclassification of unrealized (gains) losses on other than temporary impaired debt securities, net of tax of $- million and $- million, respectively for the three and six month period ended	0		1		0		1
Net unrealized holding gains (losses) arising during period, net of tax of $- million and $13 million for the three month period ended, and $- million and $8 million for the six month period ended	0		23		0		15
Reclassification adjustment for (gains) losses realized in net income, net of tax of $- million and $(4) million for the three month period ended, and $(62) million adn $(4) million for the six month period ended	0	[2]	(8)	[2]	(115)	[2]	(9)	[2]
Total other comprehensive income (loss) for period	0		15		(115)		6
Balance at end of period	0		109		0		109
Unrealized gains (losses) on other-than-temporarily impaired debt securities available-for-sale:
Balance at beginning of period	0		0		1		0
Reclassification of unrealized (gains) losses on other than temporary impaired debt securities, net of tax of $- million and $- million, for the three and six month period ended	0		(1)		0		(1)
Other-than-temporary impairment on debt securities available-for-sale recognized in other comprehensive income, net of tax of $- million and $- million, respectively	0		0		0		0
Reclassification adjustment for (gains) losses realized in net income, net of tax of $- million and $- million, for the three and six month period ended	0	[2]	1	[2]	(1)	[2]	1	[2]
Total other comprehensive income (loss) for period	0		(1)		1		(1)
Balance at end of period	0		0		0		0
Pension and postretirement benefit plan liability:
Balance at beginning and end of period	(26)		(11)		(26)		(11)
Change in unfunded pension and postretirement liability, net of tax of $- million and $- million, for the three and six month period ended	0		0		0		0
Reclassification adjustment for (gains) losses realized in net income, net of tax of $- million and $- million, for the three and six month period ended	1	[3]	1	[3]	1	[4]	1	[3]
Total other comprehensive income (loss) for period	(1)		(1)		(1)		(1)
Balance at end of period	(25)		(10)		(25)		(10)
Foreign currency translation adjustments:
Balance at beginning of period	(9)		12		11		7
Translation gains (losses), net of tax of $- million and $(1) million for the three and six month period	0		(5)		(5)		0
Reclassification adjustment for (gains) losses realized in net income, net of tax of $- million and $- million for the three month period ended and $(9) million and $- million, for the six month period ended	9	[1]	0	[1]	(6)	[1]	0	[1]
Total other comprehensive income (loss) for period	9		(5)		(11)		0
Balance at end of period	0		7		0		7
Total accumulated other comprehensive income (loss) at end of period	$ (177)		$ (338)		$ (177)		$ (338)		$ (257)

[1] See the tables below for the components of the amounts reclassified during the three and six months ended June 30, 2013 into income and location in our consolidated statement of income (loss)

[2] The amounts reclassified during the three and six months ended June 30, 2013 are included in income (loss) from discontinued operations in our consolidated statement of income (loss).

[3] The amounts reclassified during the three and six months ended June 30, 2013 are included as a component of salaries and employee benefits in our consolidated statement of income (loss).

[4] Amounts in parenthesis indicate expenses recognized in the consolidated statement of income (loss).