Equity Incentive Plan Textuals (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
EQUITY INCENTIVE PLAN [Abstract]
Number of Shares Authorized for Stock Option Plan	3,500,000
Numer of Restricted Stock Units Authorized	2,100,000
Options, Award Vesting Period	five
Award Vesting Period, Maximum	ten years and six months
Restricted Stock Units, Vesting Period	five
Performance Options, Grants in Period				213,850
Performance-based options, Grants in Period, Grant Date Fair Value				$ 32.20
Performance-based Options, Vesting Period				five
Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 42.43	$ 37.84	$ 27.82
Options, Exercises in Period, Total Intrinsic Value	$ 44.7	$ 39.3	$ 10.9
Stock Options, Vested in Period, Total Fair Value	6.8	6.9	6.5
Restricted Stock Units, Vested in Period, Total Fair Value	4.5	4.1	3.2
Number of Shares Available for Grant	1,084,417
Deferred Compensation Liability, Current and Noncurrent	$ 38.0
Estimated Weighted Average Amortization Period	2.24