Share-Based Payments (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2011
Stock Option Activity [Abstract]
Beginning Balance, Outstanding shares	7,167,000
Beginning Balance, Weighted Average Exercise Price	$ 55.43
Shares, Granted	0
Weighted Average Exercise Price, Granted	$ 0.00
Shares, Exercised	(5,235,000)
Weighted Average Exercise Price, Exercised	$ 56.40
Shares, Cancelled	(241,000)
Weighted Average Exercise Price, Cancelled	$ 53.30
Ending Balance, Outstanding shares	1,691,000
Ending Balance, Weighted Average Exercise Price	$ 52.75