Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Aug. 31, 2025	Aug. 31, 2024	Aug. 31, 2023
Income Statement [Abstract]
Operating revenues	$ 676,368	$ 607,074	$ 674,084
Cost of operating revenues	465,588	416,019	461,069
Gross profit	210,780	191,055	213,015
Operating expenses:
Selling expense	41,740	39,905	36,201
General and administrative expense	62,986	57,419	56,412
Engineering and research expense	17,930	17,123	18,218
Total operating expenses	122,656	114,447	110,831
Operating income	88,124	76,608	102,184
Other income (expense):
Interest expense	(1,833)	(3,234)	(3,788)
Interest income	7,718	5,189	2,783
Other income (expense), net	574	487	(804)
Total other income (expense)	6,459	2,442	(1,809)
Earnings before income taxes	94,583	79,050	100,375
Income tax expense	20,531	12,793	27,996
Net earnings	$ 74,052	$ 66,257	$ 72,379
Earnings per share:
Basic	$ 6.82	$ 6.04	$ 6.58
Diluted	$ 6.78	$ 6.01	$ 6.54
Shares used in computing earnings per share:
Basic	10,859	10,976	11,003
Diluted	10,918	11,017	11,062
Cash dividends declared per share	$ 1.45	$ 1.41	$ 1.37