Operating Results of Discontinued Operations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2013
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales		$ 83,903	$ 448,385
Operating income (loss) of discontinued operations	$ (4,791)	(5,735)	12,080
Pre-tax gain on disposal of discontinued business		7,079
Impairment charges			11,525
Income (loss) before income taxes	(4,791)	1,344	555
Income tax benefit	2,167	2,142	631
Income (loss) from discontinued operations, net of taxes	$ (2,624)	$ 3,486	$ 1,186