Business Segments - Reconciliation of IFRS Basis Segment Results (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Segment Reporting [Line Items]
US GAAP based Net interest income	$ 229		$ 417		$ 861		$ 1,216
US GAAP based Other operating income (Total other revenues)	114		(144)		1,096		(2,204)
US GAAP based Total operating income (loss)	343		273		1,957		(988)
US GAAP based Loan impairment charges (Provision for credit losses)	(160)		287	[1]	131		1,816	[1]
US GAAP Net interest income and other operating income less provision for credit losses	503		(14)		1,826		(2,804)
US GAAP based Operating expenses	216		276		679		730
Income (loss) from continuing operations before income tax	287		(290)		1,147		(3,534)
US GAAP based Customer loans (Receivables)	27,844		33,963		27,844		33,963
US GAAP based Assets	40,779		45,440		40,779		45,440
IFRS Basis Consolidated Totals [Member]
Segment Reporting [Line Items]
IFRS based Net interest income	491		630		1,620		1,897
IFRS based Other operating income (Total other revenues)	(28)		(171)		(343)		(919)
IFRS based Total operating income (loss)	463		459		1,277		978
IFRS based Loan impairment charges (Provision for credit losses)	115		493		558		2,068
IFRS based Net interest income and other operating income less provision for credit losses	348		(34)		719		(1,090)
IFRS based Operating expense	207		248		615		658
IFRS based Profit (loss) before tax	141		(282)		104		(1,748)
IFRS based Customer loans (Receivables)	32,436		38,754		32,436		38,754
IFRS based Assets	42,774		48,688		42,774		48,688
IFRS Adjustments [Member]
Segment Reporting [Line Items]
IFRS based Net interest income	(187)	[2]	(124)	[2]	(514)	[2]	(373)	[2]
IFRS based Other operating income (Total other revenues)	63	[2]	(76)	[2]	1,183	[2]	(1,639)	[2]
IFRS based Total operating income (loss)	(124)	[2]	(200)	[2]	669	[2]	(2,012)	[2]
IFRS based Loan impairment charges (Provision for credit losses)	(275)	[2]	(206)	[2]	(427)	[2]	(252)	[2]
IFRS based Net interest income and other operating income less provision for credit losses	151	[2]	6	[2]	1,096	[2]	(1,760)	[2]
IFRS based Operating expense	5	[2]	14	[2]	53	[2]	26	[2]
IFRS based Profit (loss) before tax	146	[2]	(8)	[2]	1,043	[2]	(1,786)	[2]
IFRS based Customer loans (Receivables)	(4,553)	[2]	(4,746)	[2]	(4,553)	[2]	(4,746)	[2]
IFRS based Assets	(1,995)	[2]	(3,248)	[2]	(1,995)	[2]	(3,248)	[2]
IFRS Reclassifications [Member]
Segment Reporting [Line Items]
IFRS based Net interest income	(75)	[3]	(89)	[3]	(245)	[3]	(308)	[3]
IFRS based Other operating income (Total other revenues)	79	[3]	103	[3]	256	[3]	354	[3]
IFRS based Total operating income (loss)	4	[3]	14	[3]	11	[3]	46	[3]
IFRS based Loan impairment charges (Provision for credit losses)	0	[3]	0	[3]	0	[3]	0	[3]
IFRS based Net interest income and other operating income less provision for credit losses	4	[3]	14	[3]	11	[3]	46	[3]
IFRS based Operating expense	4	[3]	14	[3]	11	[3]	46	[3]
IFRS based Profit (loss) before tax	0	[3]	0	[3]	0	[3]	0	[3]
IFRS based Customer loans (Receivables)	(39)	[3]	(45)	[3]	(39)	[3]	(45)	[3]
IFRS based Assets	$ 0	[3]	$ 0	[3]	$ 0	[3]	$ 0	[3]

[1] The nine months ended September 30, 2012 includes $112 million related to the lower of amortized cost or fair value attributable to credit for personal non-credit card receivables transferred to held for sale at June 30, 2012. See Note 6, "Receivables Held for Sale," for additional information.

[2] IFRSs Adjustments consist of the accounting differences between U.S. GAAP and IFRSs.

[3] Represents differences in balance sheet and income statement presentation between U.S. GAAP and IFRSs.