Income Tax Expense from Continuing Operations (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Apr. 30, 2014	Apr. 30, 2013	Apr. 30, 2012
Current:
Federal	$ 43,470	$ 38,661	$ 9,816
State	6,167	5,982	2,050
Total current	49,637	44,643	11,866
Deferred:
Deferred federal	(1,352)	1,508	778
Deferred state	(190)	349	(62)
Total deferred	(1,542)	1,857	716
Total income tax expense	$ 48,095	$ 46,500	$ 12,582

Amount of current federal tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.

Amount of current state and local tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred federal income tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

Amount of deferred state and local tax expense (benefit) pertaining to income (loss) from continuing operations.