Finance Receivables - Impaired and Non-Accrual Receivables and Troubled Debt Restructurings (Details) (Financial Services [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
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]
Recorded investment of receivables that were impaired	415	$ 435
Percentage of recorded investment of receivables that were impaired	0.80%	0.90%
Non-consumer [Member]
Financing Receivable Impaired [Abstract]
Recorded investment of receivables that were impaired	105	$ 71
Percentage of recorded investment of receivables that were impaired	0.30%	0.20%