Condensed Consolidated Statements of Shareholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Capital In Excess Of Stated Value [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss, Net [Member]
Beginning balance, value at Aug. 31, 2022	$ 393,358	$ 19,063	$ (277,238)	$ 94,006	$ 579,000	$ (21,473)
Beginning balance, shares at Aug. 31, 2022		19,063	8,083
Net earnings	36,269	$ 0	$ 0	0	36,269	0
Other comprehensive income (loss)	(726)	0	0	0	0	(726)
Total comprehensive income	35,543	0	0	0	0	0
Cash dividends per share	(7,485)	0	0	0	(7,485)	0
Issuance of common shares under share compensation plans, net	(2,233)	$ 28	$ 0	(2,261)	0	0
Issuance of common shares under share compensation plans, net, shares		28	0
Share-based compensation expense	3,089	$ 0	$ 0	3,089	0	0
Ending balance, value at Feb. 28, 2023	422,272	$ 19,091	$ (277,238)	94,834	607,784	(22,199)
Ending Balance, shares at Feb. 28, 2023		19,091	8,083
Beginning balance, value at Nov. 30, 2022	404,788	$ 19,090	$ (277,238)	93,079	593,475	(23,618)
Beginning balance, shares at Nov. 30, 2022		19,090	8,083
Net earnings	18,052	$ 0	$ 0	0	18,052	0
Other comprehensive income (loss)	1,419	0	0	0	0	1,419
Total comprehensive income	19,471	0	0	0	0	0
Cash dividends per share	(3,743)	0	0	0	(3,743)	0
Issuance of common shares under share compensation plans, net	140	$ 1	$ 0	139	0	0
Issuance of common shares under share compensation plans, net, shares		1	0
Share-based compensation expense	1,616	$ 0	$ 0	1,616	0	0
Ending balance, value at Feb. 28, 2023	422,272	$ 19,091	$ (277,238)	94,834	607,784	(22,199)
Ending Balance, shares at Feb. 28, 2023		19,091	8,083
Beginning balance, value at Aug. 31, 2023	455,651	$ 19,094	$ (277,238)	98,508	636,297	(21,010)
Beginning balance, shares at Aug. 31, 2023		19,094	8,083
Net earnings	33,142	$ 0	$ 0	0	33,142	0
Other comprehensive income (loss)	(615)	0	0	0	0	(615)
Total comprehensive income	32,527	0	0	0	0	0
Cash dividends per share	(7,724)	0	0	0	(7,724)	0
Issuance of common shares under share compensation plans, net	(755)	$ 28	$ 0	(783)	0	0
Issuance of common shares under share compensation plans, net, shares		28	0
Share-based compensation expense	3,335	$ 0	$ 0	3,335	0	0
Ending balance, value at Feb. 29, 2024	$ 483,034	$ 19,122	$ (277,238)	$ 101,060	$ 661,715	$ (21,625)
Ending Balance, shares at Feb. 29, 2024		19,122	8,083
Beginning balance, value at Nov. 30, 2023		$ 19,115	$ 8,083
Beginning balance, shares at Nov. 30, 2023	466,860	19,115	(277,238)	98,628	647,455	(21,100)
Net earnings	$ 18,123	$ 0	$ 0	$ 0	$ 18,123	$ 0
Other comprehensive income (loss)	(525)	0	0	0	0	(525)
Total comprehensive income	17,598	0	0	0	0
Cash dividends per share	(3,863)	0	0	0	(3,863)	0
Issuance of common shares under share compensation plans, net	707	$ 7	$ 0	700	0	0
Issuance of common shares under share compensation plans, net, shares		7	0
Share-based compensation expense	1,732	$ 0	$ 0	1,732	0	0
Ending balance, value at Feb. 29, 2024	$ 483,034	$ 19,122	$ (277,238)	$ 101,060	$ 661,715	$ (21,625)
Ending Balance, shares at Feb. 29, 2024		19,122	8,083