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, 2016	May 31, 2015	May 31, 2016	May 31, 2015
Net Earnings Per Share [Abstract]
Net earnings	$ 9,644	$ 12,927	$ 12,459	$ 29,490
Weighted average shares outstanding	10,709	11,690	10,997	11,965
Diluted effect of stock awards	23	30	22	35
Weighted average shares outstanding assuming dilution	10,732	11,720	11,019	12,000
Basic net earnings per share	$ 0.90	$ 1.11	$ 1.13	$ 2.46
Diluted net earnings per share	$ 0.90	$ 1.10	$ 1.13	$ 2.46