Quarterly report pursuant to Section 13 or 15(d)

Employee Stock Plans (Weighted-Average Assumptions Used To Estimate Fair Value Of Each Employee Stock Option And SARs) (Details)

v2.4.0.6
Employee Stock Plans (Weighted-Average Assumptions Used To Estimate Fair Value Of Each Employee Stock Option And SARs) (Details)
9 Months Ended
Jan. 31, 2012
years
Jan. 31, 2011
years
Employee Stock Plans [Abstract]    
Expected volatility 47.07% 47.67%
Risk-free interest rate 1.47% 1.83%
Expected option life (in years) 5.00 5.00
Expected dividend yield 0.00% 0.00%