Finance Receivables Credit Quality (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013 Rate	Dec. 31, 2012 Rate
Financing Receivable, Recorded Investment [Line Items]
Finance Receivables Credit Indicator, Percentage	100.00%	100.00%
Financing Receivable, Gross	$ 11,379	$ 10,993
Notes, Loans and Financing Receivable, Net	22,945	10,998
FICO Scores Less Than 540 [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance Receivables, Carrying Value	3,338	3,011
Finance Receivables Credit Indicator, Percentage	29.30%	27.40%
FICO score 540 to 599 [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance Receivables, Carrying Value	5,301	5,014
Finance Receivables Credit Indicator, Percentage	46.60%	45.60%
FICO score 600 to 659 [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance Receivables, Carrying Value	2,397	2,513
Finance Receivables Credit Indicator, Percentage	21.10%	22.90%
FICO score 660 and greater [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance Receivables, Carrying Value	343	455
Finance Receivables Credit Indicator, Percentage	3.00%	4.10%
Commercial Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	4,961	560
Commercial Loan [Member] | Group 1 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	287	99
Commercial Loan [Member] | Group 2 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	972	278
Commercial Loan [Member] | Group 3 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	2,257	171
Commercial Loan [Member] | Group 4 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	928	12
Commercial Loan [Member] | Group 5 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	513
Commercial Loan [Member] | Group 6 [Member]
Financing Receivable, Recorded Investment [Line Items]
Financing Receivable, Gross	$ 4