Earnings Per Share (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Earnings Per Share, Basic and Diluted [Abstract]
Shareholders' net income	$ 553	$ 466	$ 1,115	$ 1,217
Shares (in thousands):
Weighted average	278,054,000	284,891,000	281,279,000	285,247,000
Common stock equivalents	5,509,000	4,984,000	5,336,000	4,560,000
Total shares	283,563,000	289,875,000	286,615,000	289,807,000
Shareholders' net income per share basic	$ 1.99	$ 1.64	$ 3.96	$ 4.27
Shareholders net income per share effect of dilution	$ (0.04)	$ (0.03)	$ (0.07)	$ (0.07)
Shareholders' net income per share diluted	$ 1.95	$ 1.61	$ 3.89	$ 4.20
Earnings Per Share, Basic and Diluted, Other Disclosures [Abstract]
Antidilutive options	0	3,900,000	1,200,000	3,400,000
Common shares held in Treasury	89,059,772	79,439,106	89,059,772	79,439,106