Condensed Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Nov. 30, 2019	Nov. 30, 2018
Income Statement [Abstract]
Operating revenues	$ 109,393	$ 111,951
Cost of operating revenues	75,319	83,303
Gross profit	34,074	28,648
Operating expenses:
Selling expense	6,492	7,982
General and administrative expense	11,804	15,058
Engineering and research expense	3,502	3,568
Total operating expenses	21,798	26,608
Operating income	12,276	2,040
Other income (expense):
Interest expense	(1,186)	(1,205)
Interest income	615	654
Other (expense) income, net	(450)	192
Earnings before income taxes	11,255	1,681
Income tax expense	2,910	469
Net earnings	$ 8,345	$ 1,212
Earnings per share:
Basic	$ 0.77	$ 0.11
Diluted	$ 0.77	$ 0.11
Shares used in computing earnings per share:
Basic	10,795	10,766
Diluted	10,828	10,806
Cash dividends declared per share	$ 0.31	$ 0.31