Condensed Consolidated Statements of Income and Retained Earnings - USD ($)
shares in Thousands, $ in Thousands
 3 Months Ended 6 Months Ended
Jan. 31, 2017
Jan. 31, 2016
Jan. 31, 2017
Jan. 31, 2016
Net Sales $ 65,174 $ 65,367 $ 131,786 $ 133,162
Cost of Sales (46,049) (46,305) (91,936) (93,447)
Gross Profit 19,125 19,062 39,850 39,715
Selling, General and Administrative Expenses (13,538) (13,662) (31,217) (26,539)
Income from Operations 5,587 5,400 8,633 13,176
Other Income (Expense)        
Interest expense (238) (252) (489) (511)
Interest income 8 6 16 9
Other, net (113) (85) (237) (65)
Total Other Expense, Net (343) (331) (710) (567)
Income Before Income Taxes 5,244 5,069 7,923 12,609
Income Taxes (994) (1,248) (1,664) (3,365)
Net Income 4,250 3,821 6,259 9,244
Retained Earnings:        
Balance at beginning of period     149,945 142,095
Cash dividends declared and treasury stock issuances     (2,964) (2,846)
Balance at End of Period $ 153,240 $ 148,493 $ 153,240 $ 148,493
Net Income Per Share        
Diluted Common (in dollars per share) $ 0.58 $ 0.53 $ 0.86 $ 1.28
Average Shares Outstanding        
Diluted Common (in shares) 7,155 7,096 7,145 7,074
Common Stock        
Net Income Per Share        
Basic Common (in dollars per share) $ 0.63 $ 0.57 $ 0.93 $ 1.39
Average Shares Outstanding        
Basic Common (in shares) 5,019 4,982 5,011 4,978
Dividends Declared Per Share (in dollars per share) $ 0.2200 $ 0.2100 $ 0.4400 $ 0.4200
Common Class B        
Net Income Per Share        
Basic Common (in dollars per share) $ 0.47 $ 0.43 $ 0.70 $ 1.04
Average Shares Outstanding        
Basic Common (in shares) 2,088 2,055 2,077 2,046
Dividends Declared Per Share (in dollars per share) $ 0.1650 $ 0.1575 $ 0.3300 $ 0.3150