Earnings Per Share (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Basic EPS
Income from continuing operations	$ 1,327	$ 1,332	$ 2,686	$ 2,892
Discontinued operations, net	(5)	(4)	(9)	(5)
NET INCOME	1,322	1,328	2,677	2,887
Less: Net income allocated to participating securities	(3)	(2)	(5)	(4)
Net income, net of participating securities	1,319	1,326	2,672	2,883
Weighted average number of basic shares	804.9	810.3	804.8	810.4
Basic EPS (in dollars per share)	$ 1.64	$ 1.64	$ 3.32	$ 3.55
Diluted EPS
Net income, net of participating securities	$ 1,319	$ 1,326	$ 2,672	$ 2,883
Weighted average number of basic shares	804.9	810.3	804.8	810.4
Dilutive effect of potentially dilutive securities (in shares)	0.5	0.7	0.5	0.8
Total diluted weighted average common shares	805.4	811.0	805.3	811.2
Diluted EPS (in dollars per share)	$ 1.64	$ 1.64	$ 3.32	$ 3.55