Basic and Diluted 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]
Income from Continuing Operations	$ 419	$ 195	$ 811	$ 785
Earnings Adjustment from Assumed Conversion of Dilutive Shares of Common Stock in Rabbi Trust	8	0	0	0	[1]
Income (Loss) from Continuing Operations available to common stockholders, diluted	$ 411	$ 195	$ 811	$ 785
Weighted Average Number of Shares Outstanding, Basic (in shares)	362	359	361	359
Incremental Shares from Assumed Conversion of Dilutive Stock Options, Restricted Stock and Shares of Common Stock in Rabbi Trust (in shares)	5	4	6	4
Weighted Average Number of Shares Outstanding, Diluted (in shares)	367	363	367	363
Earnings from Continuing Operations Per Share, Basic (in dollars per share)	$ 1.16	$ 0.54	$ 2.25	$ 2.19
Earnings from Continuing Operations Per Share, Diluted (in dollars per share)	$ 1.12	$ 0.53	$ 2.21	$ 2.17
Number of antidilutive stock options, shares of restricted stock and shares of common stock in rabbi trust excluded from calculation above (in shares)	2	4	3	5

[1] Consistent with GAAP, when dilutive, deferred compensation gains or losses, net of tax, are excluded from net income while our common shares held in the rabbi trust are included in the diluted share count. For this reason, the diluted earnings per share calculations for the three and nine months ended September 30, 2014 exclude deferred compensation (gains) losses, net of tax. The deferred compensation loss, net of tax, excluded for the calculation of diluted earnings per share for the nine months ended September 30, 2014 was de minimis.