Debt Interest Income and Expense (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Debt Disclosure [Abstract]
Interest expense	$ 104	[1]	$ 110	[1]	$ 208	[1]	$ 220	[1]
Interest income	$ 118	[2]	$ 147	[2]	$ 237	[2]	$ 298	[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.