Debt Interest Income and Expense (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Debt Disclosure [Abstract]
Interest expense	$ 100	[1]	$ 105	[1]	$ 308	[1]	$ 325	[1]
Interest income	$ 136	[2]	$ 163	[2]	$ 373	[2]	$ 461	[2]

[1] Includes Equipment financing interest, as well as non-financing interest expense that is included in Other expenses, net in the Condensed Consolidated Statements of Income.

[2] Includes Finance income, as well as other interest income that is included in Other expenses, net in the Condensed Consolidated Statements of Income.