Summarized Results from Discontinued Operations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Jul. 31, 2014	Jul. 31, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenues from discontinued operations	$ 2,535	$ 4,252
Income from discontinued operations before income taxes	303	446
Income tax expense	23	168
Net income from discontinued operations	280	278
Loss on disposal of discontinued operations, net of tax	(1,537)
Net income (loss) from discontinued operations, net of tax	$ (1,257)	$ 278