Income Taxes Components of Provision for Income Taxes, Net (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current taxes:
U.S. Federal																	$ 214	$ 99	$ 528
U.S. State																	65	45	34
International																	204	173	131
Current taxes																	483	317	693
Deferred taxes:
U.S. Federal																	(125)	(114)	(129)
U.S. State																	(11)	(19)	(27)
International																	(180)	(23)	(109)
Deferred taxes																	(316)	(156)	(265)
Provision for income taxes, net	$ (205)	[1]	$ 205	[1]	$ (94)	[1]	$ (73)	[1]	$ (179)	[1]	$ 12	[1]	$ (13)	[1]	$ 18	[1]	$ 167	$ 161	$ 428

[1] The sum of quarterly amounts, including per share amounts, may not equal amounts reported for year-to-date periods. This is due to the effects of rounding and changes in the number of weighted-average shares outstanding for each period.