Disclosure Of Compensation Related Costs, Share Based Payments (Tables)

9 Months Ended

Jan. 31, 2012

Disclosure Of Compensation Related Costs, Share Based Payments [Abstract]

Schedule Of Issuance Of Stock Option Plans

	Number of Shares		Weighted Average Exercise Price
Outstanding April 30, 2011	775,609	$	23.38
Granted	441,000		44.39
Exercised	(96,700)		19.93
Forfeited	(3,500)		36.19
Outstanding at January 31, 2012	1,116,409	$	31.94