Finance Receivables Aging (Details) (Financial Services [Member], USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Financing Receivables [Line Items]
Number Of Days After Which Finance Receivable Is Considered Past Due	any payment, including principal and interest, that is at least 31 days past the contractual due date
Financing Receivable, Gross	$ 86,462	$ 81,173
Consumer [Member]
Financing Receivables [Line Items]
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	17	14
Financing Receivable Recorded Investment 31 To 60 Days Past Due	718	754
Financing Receivable Recorded Investment 61 To 90 Days Past Due	97	105
Financing Receivable Recorded Investment 91 To 120 Days Past Due	29	27
Financing Receivable Recorded Investment Greater Than 120 Days Past Due	52	63
Financing Receivable, Recorded Investment, Past Due	896	949
Financing Receivable, Recorded Investment, Current	53,200	49,248
Financing Receivable, Gross	54,096	50,197
Non-consumer [Member]
Financing Receivables [Line Items]
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	3	21
Financing Receivable, Recorded Investment, Past Due	117	89
Financing Receivable, Recorded Investment, Current	32,249	30,887
Financing Receivable, Gross	$ 32,366	$ 30,976
Minimum [Member]
Financing Receivables [Line Items]
Number Of Days At Which Finance Receivables Are In Process Of Collection	90 days