Discontinued Operations - Additional Information (Detail) - USD ($)		3 Months Ended
	Jun. 04, 2014	Jul. 31, 2015	Jul. 31, 2014
Discontinued Operations and Disposal Groups [Abstract]
Proceeds from disposition	$ 30,000,000		$ 30,000,000
Amount that will be placed into escrow as partial security for the Company's indemnification obligations	$ 4,500,000
Loss on disposal of discontinued operations, net of tax, recognized in current period		$ 0	$ (1,537,000)
Assets held for sale		0
Claims for indemnification received		$ 0