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, 2016	Jul. 31, 2015	Jul. 31, 2014
Earnings Per Share Note [Line Items]
Weighted-average shares outstanding for basic earnings per share	52,458,789	53,166,206	53,270,076
Stock options, unvested restricted stock and restricted stock units	131,727	109,304	91,614
Weighted-average shares outstanding assuming dilution	52,590,516	53,275,510	53,361,690