Employee Benefit Plans (Details) (USD $) In Millions, except Per Share data	1 Months Ended	9 Months Ended
	Feb. 28, 2011	Sep. 30, 2011
Activity under all stock option incentive plans
Beginning Balance, Number of Shares		78
Beginning Balance, Weighted Average Exercise Price per Share		$ 27.05
Beginning Balance, Weighted Average Grant Date Fair Value per Share		$ 15.05
Number of Shares, Options Granted	6	0	[1]
Weighted Average Exercise Price per Share, Options Granted		$ 45.82	[1]
Weighted Average Grant Date Fair Value per Share, Options Granted		$ 11.72	[1]
Number of Shares, Options Cancelled		(2)
Weighted Average Exercise Price per Share, Options Cancelled		$ 29.22
Weighted Average Grant Date Fair Value per Share, Options Cancelled		$ 11.91
Number of Shares, Options Exercised		(8)
Weighted Average Exercise Price per Share, Options Exercised		$ 23.55
Weighted Average Grant Date Fair Value per Share, Options Exercised		$ 14.78
Ending Balance, Number of Shares		68
Ending Balance, Weighted Average Exercise Price per Share		$ 27.42
Ending Balance, Weighted Average Grant Date Fair Value per Share		$ 15.23
Exercise Price Range Lower Range Limit [Member]
Activity under all stock option incentive plans
Beginning Balance, Exercise Price Range per Share		$ 0.01
Exercise Price Range per Share, Options Granted		$ 0.00	[1]
Exercise Price Range per Share, Options Cancelled		$ 0.55
Exercise Price Range per Share, Options Exercised		$ 0.01
Ending Balance, Exercise Price Range per Share		$ 0.01
Exercise Price Range Upper Range Limit [Member]
Activity under all stock option incentive plans
Beginning Balance, Exercise Price Range per Share		$ 48.63
Exercise Price Range per Share, Options Granted		$ 45.82	[1]
Exercise Price Range per Share, Options Cancelled		$ 46.01
Exercise Price Range per Share, Options Exercised		$ 45.05
Ending Balance, Exercise Price Range per Share		$ 48.63

[1] Less than one million stock options were granted in the nine months ended September 30, 2011.