Business Segments IFRS Adjustments from Previous Table (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Segment Reporting Information [Line Items]
IFRS based Net Interest Income	$ (500)	$ (522)	$ (261)
IFRS based Other operating income (Total other revenues)	(1,609)	3	(69)
IFRS based Loan impairment charges (Provision for credit losses)	332	495	341
Ifrs Based Provision for Credit Losses	44	(40)	44
Ifrs Based Total Costs and Expenses	(1,821)	16	(33)
IFRS based Customer loans (Receivables)	(4,557)	(162)	(270)
IFRS based Assets	(3,074)	(2,974)	(3,408)
Goodwill and intangible assets
Segment Reporting Information [Line Items]
IFRS based Net Interest Income		0	0
IFRS based Other operating income (Total other revenues)		0	0
IFRS based Loan impairment charges (Provision for credit losses)		0	0
Ifrs Based Provision for Credit Losses		0	5
Ifrs Based Total Costs and Expenses		0	(5)
IFRS based Customer loans (Receivables)		0	0
IFRS based Assets		(111)	0
Derivative and hedge accounting
Segment Reporting Information [Line Items]
IFRS based Net Interest Income	15	5	12
IFRS based Other operating income (Total other revenues)	0	0	0
IFRS based Loan impairment charges (Provision for credit losses)	0	0	0
Ifrs Based Provision for Credit Losses	0	0	0
Ifrs Based Total Costs and Expenses	15	5	12
IFRS based Customer loans (Receivables)	0	0	0
IFRS based Assets	(4)	0	0
Purchase Accounting [Member]
Segment Reporting Information [Line Items]
IFRS based Net Interest Income	(5)	(4)	2
IFRS based Other operating income (Total other revenues)	3	32	(10)
IFRS based Loan impairment charges (Provision for credit losses)	(14)	(14)	(23)
Ifrs Based Provision for Credit Losses	0	0	0
Ifrs Based Total Costs and Expenses	(16)	14	(31)
IFRS based Customer loans (Receivables)	19	21	(7)
IFRS based Assets	46	57	48
Deferred loan origination costs and premiums
Segment Reporting Information [Line Items]
IFRS based Net Interest Income	(15)	(30)	(68)
IFRS based Other operating income (Total other revenues)	(5)	0	0
IFRS based Loan impairment charges (Provision for credit losses)	0	0	0
Ifrs Based Provision for Credit Losses	0	0	0
Ifrs Based Total Costs and Expenses	(20)	(30)	(68)
IFRS based Customer loans (Receivables)	125	143	175
IFRS based Assets	70	83	102
Credit loss impairment provisioning
Segment Reporting Information [Line Items]
IFRS based Net Interest Income	(535)	(499)	(213)
IFRS based Other operating income (Total other revenues)	(14)	0	0
IFRS based Loan impairment charges (Provision for credit losses)	(15)	506	369
Ifrs Based Provision for Credit Losses	0	0	0
Ifrs Based Total Costs and Expenses	(564)	7	156
IFRS based Customer loans (Receivables)	(222)	(300)	(413)
IFRS based Assets	(533)	(170)	(175)
Loans held for resale
Segment Reporting Information [Line Items]
IFRS based Net Interest Income	4	6	8
IFRS based Other operating income (Total other revenues)	(1,523)	0	3
IFRS based Loan impairment charges (Provision for credit losses)	361	0	(3)
Ifrs Based Provision for Credit Losses	5	0	0
Ifrs Based Total Costs and Expenses	(1,162)	6	8
IFRS based Customer loans (Receivables)	(4,487)	(36)	(42)
IFRS based Assets	(768)	(23)	(27)
Interest recognition
Segment Reporting Information [Line Items]
IFRS based Net Interest Income	34	(2)	(2)
IFRS based Other operating income (Total other revenues)	0	0	0
IFRS based Loan impairment charges (Provision for credit losses)	0	0	0
Ifrs Based Provision for Credit Losses	0	0	5
Ifrs Based Total Costs and Expenses	34	(2)	(7)
IFRS based Customer loans (Receivables)	8	10	17
IFRS based Assets	16	(6)	(5)
Other
Segment Reporting Information [Line Items]
IFRS based Net Interest Income	2	2	0
IFRS based Other operating income (Total other revenues)	(70)	(29)	(62)
IFRS based Loan impairment charges (Provision for credit losses)	0	3	(2)
Ifrs Based Provision for Credit Losses	39	(40)	34
Ifrs Based Total Costs and Expenses	(108)	16	(98)
IFRS based Customer loans (Receivables)	0	0	0
IFRS based Assets	$ (1,901)	$ (2,804)	$ (3,351)