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								12 Months Ended
	Aug. 31, 2020	May 31, 2020	Feb. 29, 2020	Nov. 30, 2019	Aug. 31, 2019	May 31, 2019	Feb. 28, 2019	Nov. 30, 2018	Aug. 31, 2020	Aug. 31, 2019	Aug. 31, 2018
Earnings Per Share [Abstract]
Net earnings	$ 14,674	$ 10,094	$ 5,516	$ 8,345	$ 1,503	$ 2,897	$ (3,440)	$ 1,212	$ 38,629	$ 2,172	$ 20,277
Weighted average shares outstanding									10,823	10,781	10,741
Diluted effect of stock equivalents									38	29	31
Weighted average shares outstanding assuming dilution									10,861	10,810	10,772
Basic net earnings per share									$ 3.57	$ 0.20	$ 1.89
Diluted net earnings per share	$ 1.35	$ 0.93	$ 0.51	$ 0.77	$ 0.14	$ 0.27	$ (0.32)	$ 0.11	$ 3.56	$ 0.20	$ 1.88