Finance Receivables Finance Receivables Summary (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net Reported Amount	$ 22,945		$ 22,945			$ 10,998
Financing Receivable, Gross	11,379		11,379			10,993
North America [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net Reported Amount	11,968		11,968			10,998
International [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net Reported Amount	10,977		10,977
Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Business Combination, Acquired Receivables, Fair Value	3,990		3,990
Principal Collection and Recoveries on Receivables	(7,247)		(7,964)
Post-Acquisition Finance Receivables, Carrying Value					883	560
Finance Receivables Purchased	7,358		8,398
Finance Receivables - Post Acquisition - Foreign Currency Translation	(23)		(23)
Loans and Leases Receivable, Net Reported Amount	4,961		4,961
Financing Receivable, Gross	4,961		4,961			560
Commercial Loan [Member] | North America [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Business Combination, Acquired Receivables, Fair Value
Principal Collection and Recoveries on Receivables	(1,048)	(46)	(1,765)	(46)
Post-Acquisition Finance Receivables, Carrying Value					883	560
Finance Receivables Purchased	1,334	174	2,374	174
Finance Receivables - Post Acquisition - Foreign Currency Translation
Loans and Leases Receivable, Net Reported Amount	1,169	128	1,169	128
Commercial Loan [Member] | International [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Business Combination, Acquired Receivables, Fair Value	3,990		3,990
Principal Collection and Recoveries on Receivables	(6,199)		(6,199)
Post-Acquisition Finance Receivables, Carrying Value
Finance Receivables Purchased	6,024		6,024
Finance Receivables - Post Acquisition - Foreign Currency Translation	(23)		(23)
Loans and Leases Receivable, Net Reported Amount	3,792		3,792
Consumer Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net Reported Amount	15,880		15,880
Consumer Loan [Member] | North America [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net Reported Amount	9,947	7,340	9,947	7,340
Consumer Loan [Member] | International [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans and Leases Receivable, Net Reported Amount	5,933		5,933
Consumer Loan [Member] | Pre-Acquisition Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance					1,759	2,162
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net					1,580	1,958
Business Combination, Acquired Receivables, Fair Value	1,569		1,569
Principal Collection and Recoveries on Receivables	(556)		(905)
Change in Carrying Value Adjustment	(1)		(30)
Foreign Currency Translation - Finance Receivables	(41)		(41)
Financing Receivable, Gross	2,551		2,551
Consumer Loan [Member] | Pre-Acquisition Portfolio [Member] | North America [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Outstanding Balance					1,759	2,162	3,675	4,366
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net					1,580	1,958	3,358	4,027
Business Combination, Acquired Receivables, Fair Value
Principal Collection and Recoveries on Receivables	(292)	(509)	(641)	(1,096)
Change in Carrying Value Adjustment	(9)	(37)	(38)	(119)
Foreign Currency Translation - Finance Receivables
Financing Receivable, Gross	1,279	2,812	1,279	2,812
Consumer Loan [Member] | Pre-Acquisition Portfolio [Member] | International [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Business Combination, Acquired Receivables, Fair Value	1,569		1,569
Principal Collection and Recoveries on Receivables	(264)		(264)
Change in Carrying Value Adjustment	8		8
Foreign Currency Translation - Finance Receivables	(41)		(41)
Financing Receivable, Gross	1,272		1,272
Consumer Loan [Member] | Post-Acquisition Portfolio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Business Combination, Acquired Receivables, Fair Value	5,422		5,422
Principal Collection and Recoveries on Receivables	(1,314)		(1,940)
Post-Acquisition Finance Receivables, Carrying Value					9,432	8,831
Finance Receivables Purchased	2,468		3,827
Financing Receivable, Allowance for Credit Losses, Write-downs	(116)		(248)
Finance Receivables - Post Acquisition - Foreign Currency Translation	(12)		(12)
Consumer Loan [Member] | Post-Acquisition Portfolio [Member] | North America [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Business Combination, Acquired Receivables, Fair Value
Principal Collection and Recoveries on Receivables	(720)	(422)	(1,346)	(755)
Post-Acquisition Finance Receivables, Carrying Value					9,432	8,831	6,326	5,314
Finance Receivables Purchased	1,351	1,489	2,710	2,885
Financing Receivable, Allowance for Credit Losses, Write-downs	(116)	(53)	(248)	(104)
Finance Receivables - Post Acquisition - Foreign Currency Translation
Consumer Loan [Member] | Post-Acquisition Portfolio [Member] | International [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Business Combination, Acquired Receivables, Fair Value	5,422		5,422
Principal Collection and Recoveries on Receivables	(594)		(594)
Post-Acquisition Finance Receivables, Carrying Value
Finance Receivables Purchased	1,117		1,117
Financing Receivable, Allowance for Credit Losses, Write-downs
Finance Receivables - Post Acquisition - Foreign Currency Translation	$ (12)		$ (12)