Summary of Unaudited Quarterly Results (Detail) (USD $)	3 Months Ended	12 Months Ended
Jul. 31, 2014	Apr. 30, 2014	Jan. 31, 2014	Oct. 31, 2013	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2014	Jul. 31, 2013	Jul. 31, 2012
Schedule Of Quarterly Financial Information [Line Items]
Net revenue	$ 142,000,000	$ 124,000,000	$ 141,400,000	$ 110,100,000	$ 166,200,000	$ 125,800,000	$ 138,500,000	$ 119,900,000	$ 517,548,000	$ 550,363,000	$ 516,571,000
Gross profit	62,300,000	53,400,000	61,100,000	42,900,000	67,100,000	49,100,000	55,400,000	45,100,000	219,703,000	216,679,000	193,184,000
Net (loss) income	$ 11,200,000	$ 7,800,000	$ 19,300,000	$ (3,800,000)	$ 11,700,000	$ 5,200,000	$ 9,800,000	$ 4,400,000
Basic net (loss) income per share	$ 0.90	$ 0.63	$ 1.55	$ (0.30)	$ 0.96	$ 0.42	$ 0.80	$ 0.36
Diluted net (loss) income per share	$ 0.89	$ 0.61	$ 1.53	$ (0.30)	$ 0.93	$ 0.41	$ 0.78	$ 0.35

Amount of income (loss) from continuing operations attributable to the parent. Also defined as revenue less expenses and taxes from ongoing operations before extraordinary items but after deduction of those portions of income or loss from continuing operations that are allocable to noncontrolling interests.

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The amount of net income (loss) from continuing operations per each share of common stock or unit outstanding during the reporting period.

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- Definition

The amount of net income (loss) derived from continuing operations during the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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