Discontinued Operations - Calculation of Estimated Loss on Disposal of Discontinued Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Apr. 30, 2015	Apr. 30, 2014	Jul. 02, 2014
Discontinued Operations and Disposal Groups [Abstract]
Estimated cash proceeds		$ 30,500
Basis in net assets sold as of April 30, 2014		42,937	$ 43,101
Estimated costs incurred directly attributable to the transaction		658
Estimated loss before income taxes	$ (11,011)	(9,474)
Estimated income tax benefit	(282)	(282)
Estimated loss on disposal of discontinued operations, net of taxes	$ (1,537)	$ (9,192)