Business Segments - Reconciliation of Group Reporting Basis Segment Results (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015		Mar. 31, 2014
Segment Reporting [Line Items]
US GAAP based Net interest income	$ 184		$ 232
US GAAP based Other operating income (Total other revenues)	(42)		82
US GAAP based Total operating income (loss)	142		314
US GAAP based Loan impairment charges (Provision for credit losses)	27	[1]	2
US GAAP Net interest income and other operating income less provision for credit losses	115		312
US GAAP based Operating expenses	148		217
Income (loss) from continuing operations before income tax	(33)		95
US GAAP based Customer loans (Receivables)	21,729		25,481
US GAAP based Assets	30,918		35,513
Group Reporting Basis Consolidated Totals [Member]
Segment Reporting [Line Items]
Net Interest Income	281		372
Group Reporting Basis Other operating income (Total other revenues)	(78)		(84)
Group Reporting Basis Total operating income (loss)	203		288
Group Reporting Basis Loan impairment charges (Provision for credit losses)	21		118
Group Reporting Basis Net interest income and other operating income less provision for credit losses	182		170
Operating expenses	148		216
Profit (Loss) Before Tax	34		(46)
Group Reporting Basis Customer loans (Receivables)	22,492		27,283
Total Assets	32,428		37,152
Group Reporting Basis Adjustments [Member]
Segment Reporting [Line Items]
Net Interest Income	(40)	[2]	(75)	[2]
Group Reporting Basis Other operating income (Total other revenues)	(21)	[2]	105	[2]
Group Reporting Basis Total operating income (loss)	(61)	[2]	30	[2]
Group Reporting Basis Loan impairment charges (Provision for credit losses)	6	[2]	(116)	[2]
Group Reporting Basis Net interest income and other operating income less provision for credit losses	(67)	[2]	146	[2]
Operating expenses	0	[2]	5	[2]
Profit (Loss) Before Tax	(67)	[2]	141	[2]
Group Reporting Basis Customer loans (Receivables)	(735)	[2]	(1,770)	[2]
Total Assets	(1,510)	[2]	(1,639)	[2]
Group Reporting Basis Reclassifications [Member]
Segment Reporting [Line Items]
Net Interest Income	(57)	[3]	(65)	[3]
Group Reporting Basis Other operating income (Total other revenues)	57	[3]	61	[3]
Group Reporting Basis Total operating income (loss)	0	[3]	(4)	[3]
Group Reporting Basis Loan impairment charges (Provision for credit losses)	0	[3]	0	[3]
Group Reporting Basis Net interest income and other operating income less provision for credit losses	0	[3]	(4)	[3]
Operating expenses	0	[3]	(4)	[3]
Profit (Loss) Before Tax	0	[3]	0	[3]
Group Reporting Basis Customer loans (Receivables)	(28)	[3]	(32)	[3]
Total Assets	$ 0	[3]	$ 0	[3]

[1] The provision for credit losses for real estate secured receivables during the first quarter of 2015 was impacted by a release of approximately $19 million associated with a correction to our credit loss reserve calculation for a segment of our portfolio.

[2] Group Reporting Basis Adjustments consist of accounting differences between U.S. GAAP and the Group Reporting Basis which have been described in Note 18, "Business Segments," in the 2014 Form 10-K

[3] Represents differences in balance sheet and income statement presentation between U.S. GAAP and the Group Reporting Basis.