Business Segments - Reconciliation of IFRS Basis Segment Results (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Operating Statistics [Line Items]
US Gaap based Net interest income	$ 417	$ 452	$ 1,216	$ 1,407
Other operating income (Total other revenues)	(144)	(90)	(2,204)	67
US Gaap based Total operating income (loss)	273	362	(988)	1,474
US Gaap based Loan impairment charges (Provision for credit losses)	287	2,182	1,816	3,473
Net interest income and other income less provision for credit losses	(14)	(1,820)	(2,804)	(1,999)
US Gaap based Operating expenses	276	204	730	890
Loss from continuing operations before income tax	(290)	(2,024)	(3,534)	(2,889)
Intersegment revenues
US Gaap based Customer loans (Receivables)	33,963	49,799	33,963	49,799
US Gaap based Assets	45,440	54,946	45,440	54,946
Consumer [Member]
Operating Statistics [Line Items]
IFRS based Net Interest Income	573	716	1,763	2,043
IFRS based Other operating income (Total other revenues)	7	(1)	(30)	(43)
IFRS based Total operating income (loss)	580	715	1,733	2,000
IFRS based Loan impairment charges (Provision for credit losses)	493	1,822	2,069	3,972
IFRS based net interest income loss after provision for credit losses	87	(1,107)	(336)	(1,972)
IFRS based Operating expense	234	172	638	632
IFRS based Profit (loss) before tax	(147)	(1,279)	(974)	(2,604)
IFRS based Intersegment Revenues	14	20	37	54
IFRS based Customer loans (Receivables)	38,692	50,049	38,692	50,049
IFRS based Assets of Continuing Operations	41,486	48,684	41,486	48,684
All Other [Member]
Operating Statistics [Line Items]
IFRS based Net Interest Income	51	122	125	360
IFRS based Other operating income (Total other revenues)	(173)	(279)	(874)	(472)
IFRS based Total operating income (loss)	(122)	(157)	(749)	(112)
IFRS based Loan impairment charges (Provision for credit losses)	1	1
IFRS based net interest income loss after provision for credit losses	(123)	(158)	(749)	(112)
IFRS based Operating expense	13	6	26	165
IFRS based Profit (loss) before tax	(136)	(164)	(775)	(277)
IFRS based Intersegment Revenues	(14)	(13)	(30)	(35)
IFRS based Customer loans (Receivables)		110		110
IFRS based Assets of Continuing Operations	7,201	9,349	7,201	9,349
Adjustments Reconciling Items [Member]
Operating Statistics [Line Items]
IFRS based Other operating income (Total other revenues)		(7)	(7)	(19)
IFRS based Total operating income (loss)		(7)	(7)	(19)
IFRS based net interest income loss after provision for credit losses		(7)	(7)	(19)
IFRS based Operating expense		(7)	(7)	(19)
IFRS based Intersegment Revenues		(7)	(7)	(19)
IFRS Basis Consolidated Totals [Member]
Operating Statistics [Line Items]
IFRS based Net Interest Income	624	838	1,888	2,403
IFRS based Other operating income (Total other revenues)	(166)	(287)	(911)	(534)
IFRS based Total operating income (loss)	458	551	977	1,869
IFRS based Loan impairment charges (Provision for credit losses)	494	1,823	2,069	3,972
IFRS based net interest income loss after provision for credit losses	(36)	(1,272)	(1,092)	(2,103)
IFRS based Operating expense	247	171	657	778
IFRS based Profit (loss) before tax	(283)	(1,443)	(1,749)	(2,881)
IFRS based Customer loans (Receivables)	38,692	50,159	38,692	50,159
IFRS based Assets of Continuing Operations	48,687	58,033	48,687	58,033
IFRS Adjustments [Member]
Operating Statistics [Line Items]
IFRS based Net Interest Income	(123)	(239)	(372)	(535)
IFRS based Other operating income (Total other revenues)	(77)	21	(1,640)	39
IFRS based Total operating income (loss)	(200)	(218)	(2,012)	(496)
IFRS based Loan impairment charges (Provision for credit losses)	(207)	359	(253)	(499)
IFRS based net interest income loss after provision for credit losses	7	(577)	(1,759)	3
IFRS based Operating expense	14	4	26	11
IFRS based Profit (loss) before tax	(7)	(581)	(1,785)	(8)
IFRS based Customer loans (Receivables)	(4,729)	(250)	(4,729)	(250)
IFRS based Assets of Continuing Operations	(3,247)	(3,087)	(3,247)	(3,087)
IFRS Reclassifications [Member]
Operating Statistics [Line Items]
IFRS based Net Interest Income	(84)	(147)	(300)	(461)
IFRS based Other operating income (Total other revenues)	99	176	347	562
IFRS based Total operating income (loss)	15	29	47	101
IFRS based net interest income loss after provision for credit losses	15	29	47	101
IFRS based Operating expense	15	29	47	101
IFRS based Customer loans (Receivables)		$ (110)		$ (110)