Condensed Consolidated Statements of Earnings - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Feb. 28, 2025	Feb. 29, 2024	Feb. 28, 2025	Feb. 29, 2024
Income Statement [Abstract]
Operating revenues	$ 187,064	$ 151,519	$ 353,345	$ 312,877
Cost of operating revenues	124,576	102,565	240,891	214,018
Gross profit	62,488	48,954	112,454	98,859
Operating expenses:
Selling expense	10,850	9,498	21,062	19,315
General and administrative expense	15,352	13,466	30,360	28,128
Engineering and research expense	4,162	3,892	8,026	8,244
Total operating expenses	30,364	26,856	59,448	55,687
Operating income	32,124	22,098	53,006	43,172
Other income (expense):
Interest expense	(402)	(830)	(1,154)	(1,707)
Interest income	1,843	1,295	3,088	2,363
Other income (expense), net	(351)	134	307	(136)
Total other income (expense)	1,090	599	2,241	520
Earnings before income taxes	33,214	22,697	55,247	43,692
Income tax expense	6,638	4,574	11,508	10,550
Net earnings	$ 26,576	$ 18,123	$ 43,739	$ 33,142
Earnings per share:
Basic	$ 2.45	$ 1.64	$ 4.03	$ 3.01
Diluted	$ 2.44	$ 1.64	$ 4.01	$ 2.99
Shares used in computing earnings per share:
Basic	10,863	11,033	10,858	11,025
Diluted	10,909	11,074	10,906	11,067
Cash dividends declared per share	$ 0.36	$ 0.35	$ 0.72	$ 0.7