Earning Per Common Share (Detail) - shares	3 Months Ended		9 Months Ended
	Apr. 30, 2018	Apr. 30, 2017	Apr. 30, 2018	Apr. 30, 2017
Earnings Per Share [Abstract]
Weighted-average shares outstanding for basic earnings per share	52,695,365	52,582,134	52,667,016	52,555,792
Unvested restricted stock and restricted stock units	158,176	190,972	177,024	183,924
Weighted-average shares outstanding assuming dilution	52,853,541	52,773,106	52,844,040	52,739,716