Earnings Per Common Share - Weighted Average Shares (Details) - shares
3 Months Ended 6 Months Ended
Jan. 31, 2016
Jan. 31, 2015
Jan. 31, 2016
Jan. 31, 2015
Reconciliation of weighted average number of shares and common stock equivalents attributable to common stock, to the entity's total weighted average number of shares and common stock equivalents, including participating securities        
Denominator for diluted earnings per share - weighted average number of shares and common stock equivalents attributable to common stock 41,404,375 41,236,847 41,364,489 41,155,396
Participating securities (in shares) 343,346 346,684 344,004 413,472
Total weighted average number of shares and common stock equivalents attributable to both common stock and participating securities 41,747,721 41,583,531 41,708,493 41,568,868