Stock Compensation Plans (Details) (USD $) In Millions, except Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Stock Compensation Plans
Restricted stock units ("RSUs")	$ 31	$ 29	$ 108	$ 99
Performance plans	24	10	59	51
Stock options	2	3	7	13
Employee stock purchase plans	2	1	5	3
Total stock compensation expense	59	43	179	166
Status of non-vested stock awards
Non-vested at beginning of period (in shares)			10,674,000	12,850,000
Granted (in shares)			4,831,000	4,984,000
Vested (in shares)			(4,850,000)	(6,288,000)
Forfeited (in shares)			(410,000)	(412,000)
Non-vested at end of period (in shares)	10,245,000	11,134,000	10,245,000	11,134,000
Weighted Average Fair value
Non-vested at beginning of period (in dollars per share)			$ 38	$ 36
Granted (in dollars per share)			$ 50	$ 39
Vested (in dollars per share)			$ 42	$ 35
Forfeited (in dollars per share)			$ 39	$ 38
Non-vested at end of period (in dollars per share)	$ 42	$ 38	$ 42	$ 38
Potential RSUs to be issued based on current performance levels (in shares)	5,791,000	4,883,000	5,791,000	4,883,000
Unamortized expense, based on current performance levels	$ 107	$ 107	$ 107	$ 107
2008 Leadership Performance Plan ("LPP") cycle
Employee Stock Options and Stock Awards
Shares granted			1,200,000
2007 Leadership Performance Plan ("LPP") cycle
Employee Stock Options and Stock Awards
Shares granted				1,700,000
2006 performance plan
Employee Stock Options and Stock Awards
Shares granted			300,000
Incentive compensation plans
Employee Stock Options and Stock Awards
Shares granted			3,300,000	3,300,000