Earnings Per Common Share (Detail) - shares	3 Months Ended		9 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2017	Apr. 30, 2016
Earnings Per Share [Abstract]
Weighted-average common shares outstanding for basic earnings per common share	52,582,134	52,474,801	52,555,792	52,453,025
Unvested restricted stock and restricted stock units	190,972	126,872	183,924	116,269
Weighted-average common shares outstanding for diluted earnings per common share	52,773,106	52,601,673	52,739,716	52,569,294