Business Segments - Reconciliation of IFRS Basis Segment Results (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013
Segment Reporting [Line Items]
US GAAP based Net interest income	$ 225		$ 238		$ 457		$ 632
US GAAP based Other operating income (Total other revenues)	47		628		129		982
US GAAP based Total operating income (loss)	272		866		586		1,614
US GAAP based Loan impairment charges (Provision for credit losses)	(197)		267		(195)		291
US GAAP Net interest income and other operating income less provision for credit losses	469		599		781		1,323
US GAAP based Operating expenses	121		195		338		463
Income from continuing operations before income tax	348		404		443		860
US GAAP based Customer loans (Receivables)	24,473		29,112		24,473		29,112
US GAAP based Assets	34,338		41,872		34,338		41,872
IFRS Basis Consolidated Totals [Member]
Segment Reporting [Line Items]
Net Interest Income	370		493		742		1,129
IFRS based Other operating income (Total other revenues)	(77)		(116)		(161)		(315)
IFRS based Total operating income (loss)	293		377		581		814
IFRS based Loan impairment charges (Provision for credit losses)	11		124		129		443
IFRS based Net interest income and other operating income less provision for credit losses	282		253		452		371
Provision For Credit Losses	124		153		340		408
IFRS based Profit (loss) before tax	158		100		112		(37)
IFRS based Customer loans (Receivables)	26,379		34,498		26,379		34,498
Total Assets	35,784		43,839		35,784		43,839
IFRS Adjustments [Member]
Segment Reporting [Line Items]
Net Interest Income	(80)	[1]	(168)	[1]	(155)	[1]	(327)	[1]
IFRS based Other operating income (Total other revenues)	67	[1]	658	[1]	172	[1]	1,120	[1]
IFRS based Total operating income (loss)	(13)	[1]	490	[1]	17	[1]	793	[1]
IFRS based Loan impairment charges (Provision for credit losses)	(209)	[1]	143	[1]	(325)	[1]	(152)	[1]
IFRS based Net interest income and other operating income less provision for credit losses	196	[1]	347	[1]	342	[1]	945	[1]
Provision For Credit Losses	6	[1]	43	[1]	11	[1]	48	[1]
IFRS based Profit (loss) before tax	190	[1]	304	[1]	331	[1]	897	[1]
IFRS based Customer loans (Receivables)	(1,871)	[1]	(5,346)	[1]	(1,871)	[1]	(5,346)	[1]
Total Assets	(1,446)	[1]	(1,967)	[1]	(1,446)	[1]	(1,967)	[1]
IFRS Reclassifications [Member]
Segment Reporting [Line Items]
Net Interest Income	(65)	[2]	(87)	[2]	(130)	[2]	(170)	[2]
IFRS based Other operating income (Total other revenues)	57	[2]	86	[2]	118	[2]	177	[2]
IFRS based Total operating income (loss)	(8)	[2]	(1)	[2]	(12)	[2]	7	[2]
IFRS based Loan impairment charges (Provision for credit losses)	1	[2]	0	[2]	1	[2]	0	[2]
IFRS based Net interest income and other operating income less provision for credit losses	(9)	[2]	(1)	[2]	(13)	[2]	7	[2]
Provision For Credit Losses	(9)	[2]	(1)	[2]	(13)	[2]	7	[2]
IFRS based Profit (loss) before tax	0	[2]	0	[2]	0	[2]	0	[2]
IFRS based Customer loans (Receivables)	(35)	[2]	(40)	[2]	(35)	[2]	(40)	[2]
Total Assets	$ 0	[2]	$ 0	[2]	$ 0	[2]	$ 0	[2]

[1] IFRSs Adjustments consist of the accounting differences between U.S. GAAP and IFRSs which have been described in Note 18, "Business Segments," in the 2013 Form 10-K.

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