Finance Receivables - Impaired and Non-Accrual Receivables and Troubled Debt Restructurings (Details) (Financial Services [Member], USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Dec. 31, 2014
Financing Receivable Impaired [Abstract]
Number of Days Past Due After Which Consumer Receivables are Considered Impaired	greater than 120 days past due
Consumer [Member]
Financing Receivable Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	396	$ 415
Impaired Financing Receivable Recorded Investment, Percentage of Receivable	0.70%	0.80%
Non-consumer [Member]
Financing Receivable Impaired [Abstract]
Impaired Financing Receivable, Recorded Investment	126	$ 105
Impaired Financing Receivable Recorded Investment, Percentage of Receivable	0.40%	0.30%
Minimum [Member] | Finance Receivables [Member] | Consumer [Member]
Financing Receivable Impaired [Line Items]
Number Of Days At Which Finance Receivables Are Put In Non Accrual Status	120 days