Earnings Per Common Share (Detail) - shares	3 Months Ended		9 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2016	Apr. 30, 2015
Earnings Per Share Disclosure [Line Items]
Weighted-average common shares outstanding for basic earnings per share	52,474,801	53,380,651	52,453,025	53,363,872
Unvested restricted stock and restricted stock units	126,872	114,848	116,269	97,598
Weighted-average common shares outstanding for diluted earnings per share	52,601,673	53,495,499	52,569,294	53,461,470