Earnings Per Share (Details) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Antidilutive Options Table [Abstract]
Antidilutive options	2,400,000	2,900,000	3,100,000	3,500,000
Statement Line Items [Line Items]
Shareholders' net income	$ 380	$ 391	$ 751	$ 804
Shares (in thousands):
EPS	$ 1.33	$ 1.46	$ 2.63	$ 2.98
Earnings Per Share Text Details [Abstract]
Common shares held in Treasury	77,780,090	80,740,132	77,780,090	80,740,132
Earnings Per Share Basic Member
Shares (in thousands):
Weighted average	285,690,000	268,557,000	285,425,000	269,464,000
Total shares	285,690,000	268,557,000	285,425,000	269,464,000
EPS	$ 1.33	$ 1.46	$ 2.63	$ 2.98
Effect Of Dilution [Member]
Shares (in thousands):
Common stock equivalents	4,857,000	4,176,000	4,348,000	3,836,000
Total shares	4,857,000	4,176,000	4,348,000	3,836,000
EPS	$ (0.02)	$ (0.03)	$ (0.04)	$ (0.04)
Earnings Per Share Diluted [Member]
Shares (in thousands):
Weighted average	285,690,000	268,557,000	285,425,000	269,464,000
Common stock equivalents	4,857,000	4,176,000	4,348,000	3,836,000
Total shares	290,547,000	272,733,000	289,773,000	273,300,000
EPS	$ 1.31	$ 1.43	$ 2.59	$ 2.94