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, 2019	May 31, 2019	Feb. 28, 2019	Nov. 30, 2018	Aug. 31, 2018	May 31, 2018	Feb. 28, 2018	Nov. 30, 2017	Aug. 31, 2019	Aug. 31, 2018	Aug. 31, 2017
Earnings Per Share [Abstract]
Net earnings	$ 1,503	$ 2,897	$ (3,440)	$ 1,212	$ 4,978	$ 10,379	$ 1,735	$ 3,185	$ 2,172	$ 20,277	$ 23,179
Weighted average shares outstanding									10,781	10,741	10,666
Diluted effect of stock equivalents									29	31	28
Weighted average shares outstanding assuming dilution									10,810	10,772	10,694
Basic net earnings per share									$ 0.20	$ 1.89	$ 2.17
Diluted net earnings per share	$ 0.14	$ 0.27	$ (0.32)	$ 0.11	$ 0.46	$ 0.96	$ 0.16	$ 0.30	$ 0.20	$ 1.88	$ 2.17