Share-Based Compensation (Details 1) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 Y
Summary of stock option activity
Outstanding Stock Options, Beginning balance	17,438
Outstanding Weighted Average Exercise Price, Beginning	$ 66.76
Options granted, Stock Options	1,617
Options granted, Weighted Average Exercise Price	$ 60.07
Options exercised, Stock Options	(1,137)
Options exercised, Weighted Average Exercise Price	$ 35.21
Options cancelled, Stock Options	(416)
Options cancelled, Weighted Average Exercise Price	$ 59.32
Options expired, Stock Options	(754)
Options expired, Weighted Average Exercise Price	$ 75.21
Outstanding Stock Options, Ending balance	16,748
Outstanding Weighted Average Exercise Price, Ending	$ 68.04
Outstanding, Weighted Average Remaining Contractual Life	5.4
Outstanding, Intrinsic Value	$ 27.2
Number of outstanding options, Vested and Expected to Vest	16,224
Weighted average exercise price per share, Vested and Expected to Vest	$ 68.40
Weighted average remaining contractual life, Vested and Expected to Vest	5.3
Intrinsic value, Vested and Expected to Vest	26.0
Exercisable, Stock Options	12,608
Exercisable, Weighted Average Exercise Price	$ 71.30
Exercisable, Weighted Average Remaining Contractual Life	4.5
Exercisable, Intrinsic Value	$ 16.5