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, 2021	$ 338,445	$ 18,991	$ (277,238)	$ 86,495	$ 528,130	$ (17,933)
Beginning balance, shares at Aug. 31, 2021		18,991	8,083
Net earnings	7,901	$ 0	$ 0	0	7,901	0
Other comprehensive loss	(3,358)	0	0	0	0	(3,358)
Total comprehensive income	4,543	0	0	0	0	0
Cash dividends per share	(3,621)	0	0	0	(3,621)	0
Issuance of common shares under share compensation plans, net	1,354	$ 65	$ 0	1,289	0	0
Issuance of common shares under share compensation plans, net, shares		65	0
Share-based compensation expense	1,222	$ 0	$ 0	1,222	0	0
Ending balance, value at Nov. 30, 2021	341,943	$ 19,056	$ (277,238)	89,006	532,410	(21,291)
Ending Balance, shares at Nov. 30, 2021		19,056	8,083
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	18,217	$ 0	$ 0	0	18,217	0
Other comprehensive loss	(2,145)	0	0	0	0	(2,145)
Total comprehensive income	16,072	0	0	0	0	0
Cash dividends per share	(3,742)	0	0	0	(3,742)	0
Issuance of common shares under share compensation plans, net	(2,373)	$ 27	$ 0	(2,400)	0	0
Issuance of common shares under share compensation plans, net, shares		27	0
Share-based compensation expense	1,473	$ 0	$ 0	1,473	0	0
Ending balance, value at Nov. 30, 2022	$ 404,788	$ 19,090	$ (277,238)	$ 93,079	$ 593,475	$ (23,618)
Ending Balance, shares at Nov. 30, 2022		19,090	8,083