Interest Income and Expense (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Debt Disclosure [Abstract]
Interest expense	$ 104	[1]	$ 109	[1]
Interest income	$ 120	[2]	$ 151	[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.