XML 29 R31.htm IDEA: XBRL DOCUMENT

Components of Stock-Based Compensation Expense Recognized (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Oct. 31, 2012	Oct. 31, 2011	Oct. 31, 2012	Oct. 31, 2011
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense, pre-tax	$ 3,073	$ 3,427	$ 6,269	$ 6,597
Tax benefit from stock-based compensation expense	(1,581)	(1,182)	(2,745)	(2,328)
Total stock-based compensation expense, net of tax	1,492	2,245	3,524	4,269
Restricted Stock
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense, pre-tax	2,847	3,137	5,833	5,921
Stock Options And Stock Appreciation Rights
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense, pre-tax	226	187	436	445
Employee Stock Purchase Plan
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Total stock-based compensation expense, pre-tax		$ 103		$ 231

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References+ Details