Equity Incentive Plan Textuals (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
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	5 years
Restricted Stock Units, Vesting Period	five
Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 46.72	$ 42.43	$ 37.84
Options, Exercises in Period, Total Intrinsic Value	$ 50.9	$ 44.7	$ 39.3
Stock Options, Vested in Period, Total Fair Value	6.9	6.8	6.9
Restricted Stock Units, Vested in Period, Total Fair Value	5.3	4.5	4.1
Number of Shares Available for Grant	925,597
Deferred Compensation Liability, Current and Noncurrent	$ 13.2
Estimated Weighted Average Amortization Period	2 years 3 months 18 days