Condensed Consolidated Statements of Income and Retained Earnings (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Apr. 30, 2012	Apr. 30, 2011	Apr. 30, 2012	Apr. 30, 2011
Net Sales	$ 59,780	$ 55,538	$ 179,565	$ 169,024
Cost of Sales	(45,075)	(43,631)	(136,103)	(131,417)
Gross Profit	14,705	11,907	43,462	37,607
Selling, General and Administrative Expenses	(11,743)	(9,129)	(33,875)	(27,953)
Income from Operations	2,962	2,778	9,587	9,654
Other Income (Expense)
Interest expense	(529)	(550)	(1,557)	(1,495)
Interest income	8	37	22	75
Other, net	193	359	334	424
Total Other Income (Expense), Net	(328)	(154)	(1,201)	(996)
Income Before Income Taxes	2,634	2,624	8,386	8,658
Income taxes	(742)	(764)	(2,180)	(2,502)
Net Income	1,892	1,860	6,206	6,156
Retained Earnings
Retained Earnings at beginning of year			121,388	116,917
Cash dividends declared and treasury stock issuances			(3,475)	(3,449)
Retained Earnings - April 30	$ 124,119	$ 119,624	$ 124,119	$ 119,624
Net Income Per Share
Diluted (in dollars per share)	$ 0.26	$ 0.26	$ 0.86	$ 0.86
Average Shares Outstanding
Diluted (in shares)	7,117	7,076	7,116	7,105
Common Stock
Net Income Per Share
Basic Common (in dollars per share)	$ 0.28	$ 0.28	$ 0.93	$ 0.93
Average Shares Outstanding
Basic Common (in shares)	5,115	5,069	5,118	5,079
Common Class B
Net Income Per Share
Basic Common (in dollars per share)	$ 0.21	$ 0.22	$ 0.70	$ 0.72
Average Shares Outstanding
Basic Common (in shares)	1,938	1,914	1,932	1,906