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, 2020	May 31, 2019	May 31, 2020	May 31, 2019
Earnings Per Share [Abstract]
Net earnings	$ 10,094	$ 2,897	$ 23,955	$ 669
Weighted average shares outstanding	10,835	10,786	10,818	10,779
Diluted effect of stock awards	42	28	36	28
Weighted average shares outstanding assuming dilution	10,877	10,814	10,854	10,807
Basic net earnings per share	$ 0.93	$ 0.27	$ 2.21	$ 0.06
Diluted net earnings per share	$ 0.93	$ 0.27	$ 2.21	$ 0.06