Summary of Significant Accounting Policies (Earnings Per Share) (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Basic earnings per share - continuing operations:
Income from continuing operations, net of tax	$ 496	$ 463	$ 1,046	$ 615
Weighted average common shares outstanding (in shares)	326,000,000	326,000,000	326,000,000	326,000,000
Basic earnings per share – continuing operations (in dollars per share)	$ 1.52	$ 1.42	$ 3.21	$ 1.88
Diluted earnings per share - continuing operations:
Income from continuing operations, net of tax	496	463	1,046	615
Income impact of assumed conversions	0	0	1	1
Income from continuing operations available to common shareholders and assumed conversions	$ 496	$ 463	$ 1,047	$ 616
Weighted average common shares outstanding (in shares)	326,000,000	326,000,000	326,000,000	326,000,000
Incremental shares from assumed conversions (in shares)	3,000,000	2,000,000	3,000,000	3,000,000
Adjusted weighted average shares - diluted (in shares)	329,000,000	328,000,000	329,000,000	329,000,000
Diluted earnings per share – continuing operations (in dollars per share)	$ 1.51	$ 1.41	$ 3.18	$ 1.87
Stock-Based Compensation Awards
Diluted earnings per share - continuing operations:
Stock-based compensation awards excluded from the computation of diluted earnings per share (in shares)	38,800	4,109,363	62,885	4,109,363