Earnings Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share [Abstract]
Net Income	$ 357	$ 1,369	$ 1,371	$ 2,061
Basic weighted average shares outstanding	834	851	840	850
Dilutive effect of share-based awards	9	10	9	8
Diluted weighted average shares outstanding	843	861	849	858
Basic Earnings Per Share	$ 0.43	$ 1.61	$ 1.63	$ 2.42
Diluted Earnings Per Share	$ 0.42	$ 1.59	$ 1.61	$ 2.40