Net Earnings Per Share (Schedule Of Computation Of Basic And Diluted Net Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	May 31, 2018	May 31, 2017	May 31, 2018	May 31, 2017
Earnings Per Share [Abstract]
Net earnings	$ 10,379	$ 10,952	$ 15,299	$ 16,837
Weighted average shares outstanding	10,757	10,677	10,735	10,657
Diluted effect of stock awards	28	28	28	25
Weighted average shares outstanding assuming dilution	10,785	10,705	10,763	10,682
Basic net earnings per share	$ 0.96	$ 1.03	$ 1.43	$ 1.58
Diluted net earnings per share	$ 0.96	$ 1.02	$ 1.42	$ 1.58