Schedule of Difference Between Basic and Diluted EPS as Result of Outstanding Stock Options, Unvested Restricted Stock and Restricted Stock Units (Detail) - shares	12 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2013
Earnings Per Share Note [Line Items]
Weighted average shares outstanding for basic earnings per share	53,166,206	53,270,076	53,005,576
Stock options and unvested restricted stock and restricted stock units	109,304	91,614	109,972
Weighted average shares outstanding assuming dilution	53,275,510	53,361,690	53,115,548