Earnings Per Common Share (Detail)	3 Months Ended		6 Months Ended
	Jan. 31, 2015	Jan. 31, 2014	Jan. 31, 2015	Jan. 31, 2014
Earnings Per Share Disclosure [Line Items]
Weighted average common shares outstanding for basic earnings per share	53,377,440	53,289,626	53,355,757	53,247,315
Stock options, unvested restricted stock and restricted stock units	81,091	63,401	88,973	78,936
Weighted average common shares outstanding for diluted earnings per share	53,458,531	53,353,027	53,444,730	53,326,251