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Stock Based Compensation (Policies)
9 Months Ended
Sep. 30, 2011
Notes to Financial Statements [Abstract] 
Stock Based CompensationRoper records compensation expense for employee stock options based on the estimated fair value of the options on the date of grant using the Black-Scholes option-pricing model. Historical data, among other factors, is used to estimate the expected price volatility, the expected dividend yield, the expected option life and the expected forfeiture rate. The risk-free rate is based on the U.S. Treasury yield curve in effect at the time of grant for the estimated life of the option