Compensation and Benefit Plans (Details 2) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Stock Options
Outstanding, at the beginning of period (in options)			19,142,209
Granted (in options)			3,314,149
Expired (in options)			(87,641)
Forfeited (in options)			(244,066)
Exercised (in options)			(1,002,771)
Outstanding, at the end of period (in options)	21,121,880		21,121,880
Vested and expected to vest, at the end of period (in options)	20,639,870		20,639,870
Exercisable, at the end of period (in options)	12,613,025		12,613,025
Weighted-Average Exercise Price
Outstanding, at the beginning of period (in dollars per option)			$ 33.28
Granted (in dollars per option)	$ 37.95		$ 37.95
Expired (in dollars per option)	$ 47.93		$ 47.93
Forfeited (in dollars per option)	$ 32.52		$ 32.52
Exercised (in dollars per option)	$ 24.74		$ 24.74
Outstanding, at the end of period (in dollars per option)	$ 34.37		$ 34.37
Vested and expected to vest, at the end of period (in dollars per option)	$ 34.38		$ 34.38
Exercisable, at the end of period (in dollars per option)	$ 34.70		$ 34.70
Weighted-Average Remaining Contractual Term (Years)
Outstanding, at the end of period (in years)			6.26
Vested and expected to vest, at the end of period (in years)			6.21
Exercisable, at the end of period (in years)			4.74
Aggregate Intrinsic Value
Vested and expected to vest, at the end of period	$ 136		$ 136
Exercisable, at the end of period			93
Supplemental Data on Stock Based Compensation
Stock Based Compensation Expense	11	9	17	17
Income tax benefits related to stock compensation expense	5	4	7	7
Excess tax benefits	2	1	4	2
Cash used to purchase shares to settle options	20	6	39	13
Cash from participants to exercise stock options	12	4	25	9
Value of options exercised	8	2	14	4
Value of shares settled			5
Tax benefits realized from settlement of awards			2
Performance Shares
Weighted-Average Fair Value
Total unrecognized compensation cost	6		6
Weighted-average period, recognition of unrecognized compensation cost (in years)			2
Performance shares classified as equity awards
Performance Shares
Nonvested, at the beginning of the period (in shares)			415,028
Granted (in shares)			148,697
Forfeited (in shares)			(113,762)
Nonvested, at the end of the period (in shares)	449,963		449,963
Weighted-Average Fair Value
Nonvested, at the beginning of the period (in dollars per share)			$ 30.99
Granted (in dollars per share)			$ 27.96
Forfeited (in dollars per share)	$ 43.42		$ 43.42
Nonvested, at the end of the period (in dollars per share)	$ 28.04		$ 28.04
Performance shares classified as liability awards
Performance Shares
Nonvested, at the beginning of the period (in shares)			415,028
Granted (in shares)			148,697
Forfeited (in shares)			(113,762)
Nonvested, at the end of the period (in shares)	449,963		449,963
Weighted-Average Fair Value
Nonvested, at the beginning of the period (in dollars per share)			$ 34.74
Nonvested, at the end of the period (in dollars per share)	$ 29.43		$ 29.43
Restricted Stock Units
Performance Shares
Nonvested, at the beginning of the period (in shares)			644,796
Granted (in shares)			247,408
Forfeited (in shares)			(16,467)
Paid out (in shares)			(104,420)
Nonvested, at the end of the period (in shares)	771,317		771,317
Weighted-Average Fair Value
Nonvested, at the beginning of the period (in dollars per share)			$ 32.18
Granted (in dollars per share)			$ 37.95
Forfeited (in dollars per share)	$ 32.13		$ 32.13
Paid out (in dollars per share)			$ 52.35
Nonvested, at the end of the period (in dollars per share)	$ 31.98		$ 31.98
Total unrecognized compensation cost	12		12
Compensation cost to be recognized in 2011	4		4
Compensation cost to be recognized in 2012	5		5
Compensation cost to be recognized in 2013	3		3
Stock Options
Weighted-Average Fair Value
Total unrecognized compensation cost	$ 28		$ 28
Weighted-average period, recognition of unrecognized compensation cost (in years)			3