Finance Receivables - Impaired and Non-Accrual Receivables and Troubled Debt Restructurings (Details) (Financial Services [Member], USD $) In Millions, unless otherwise specified	12 Months Ended					12 Months Ended
	Dec. 31, 2012	Dec. 31, 2012 Consumer [Member]	Dec. 31, 2011 Consumer [Member]	Dec. 31, 2012 Non-consumer [Member]	Dec. 31, 2011 Non-consumer [Member]	Dec. 31, 2012 Minimum [Member] Finance Receivables [Member] Consumer [Member]
Financing Receivable Impaired [Abstract]
Number of Days Past Due After Which Consumer Receivables are Considered Impaired	greater than 120 days past due
Recorded investment of receivables that were impaired		$ 422	$ 382	$ 47	$ 64
Percentage of recorded investment of receivables that were impaired		0.90%	0.80%	0.20%	0.20%
Finance Receivables Non Accrual [Abstract]
Number Of Days At Which Finance Receivables Are Put In Non Accrual Status						120 days
Financing Receivable, Recorded Investment, Nonaccrual Status		304	402	29	27
Financing Receivable, Recorded Investment, Nonaccrual Status, Percentage of Receivable		0.60%	0.90%	0.10%	0.10%
Troubled Debt Restructurings [Abstract]
Financing Receivable, Modifications, Recorded Investment		249	370
Financing Receivable, Modifications, Recorded Investment, Percentage of Receivable		0.50%	0.80%
Financing Receivables, Modifications, Contracts Subsequently Defaulted, Default Rate		5.80%	3.70%
Financing Receivable, Allowance for Credit Losses Related to Consumer Troubled Debt Restructurings		$ 19	$ 16