CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Stock Held in Trust	Deferred Compensation Liability	Treasury Stock, Common
Shares, Issued at Aug. 31, 2021		83,022
Beginning Balance at Aug. 31, 2021	$ 412,198	$ 16,604	$ 202,971	$ 953,339	$ (92,984)	$ (3,067)	$ 3,067	$ (667,732)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net earnings (loss)	15,686			15,686
Total other comprehensive income (loss), net of tax	(41,977)				(41,977)
Company stock contribution to employee benefit plans and other (in shares)		15
Company stock contribution to employee benefit plans and other	269	$ 3	266
Restricted stock awards, vesting and withhold to cover (in shares)		350
Restricted stock awards issuance and vesting	0	$ 70	(70)
Cash dividend ($0.04 per share)	(2,274)			(2,274)
Treasury stock repurchases	(75,112)							75,112
Stock based compensation expense	13,619		13,619
Stock issued to, acquired for and distributed from rabbi trust (in shares)		10
Stock issued to, acquired for and distributed from rabbi trust	(152)	$ (2)	(150)			142	(142)
Shares, Issued at Aug. 31, 2022		83,397
Ending Balance at Aug. 31, 2022	318,611	$ 16,679	212,986	966,751	(134,961)	(3,209)	3,209	(742,844)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustments to Additional Paid in Capital, Other	3,950		(3,950)
Net earnings (loss)	46,561			46,561
Total other comprehensive income (loss), net of tax	13,751				13,751
Company stock contribution to employee benefit plans and other (in shares)		9
Company stock contribution to employee benefit plans and other	193	$ 2	191
Restricted stock awards, vesting and withhold to cover (in shares)		273
Restricted stock awards issuance and vesting	0	$ 54	(54)
Cash dividend ($0.04 per share)	(2,200)			(2,200)
Treasury stock repurchases	(57,662)							57,662
Stock based compensation expense	$ 8,699		8,699
Stock option exercises (in shares)	43
Stock Issued During Period, Value, Stock Options Exercised	$ 973	$ 8	965
Stock issued to, acquired for and distributed from rabbi trust (in shares)		39
Stock issued to, acquired for and distributed from rabbi trust	(318)	$ 9	(309)			275	(275)
Shares, Issued at Aug. 31, 2023		83,761
Ending Balance at Aug. 31, 2023	326,620	$ 16,752	220,472	1,011,112	(121,210)	(3,484)	3,484	(800,506)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustments to Additional Paid in Capital, Other	2,624		2,624
Retained earnings	1,011,112
Net earnings (loss)	85,749			85,749
Total other comprehensive income (loss), net of tax	4,812				4,812
Company stock contribution to employee benefit plans and other (in shares)		7
Company stock contribution to employee benefit plans and other	229	$ 2	227
Restricted stock awards, vesting and withhold to cover (in shares)		238
Restricted stock awards issuance and vesting	0	$ 47	(47)
Cash dividend ($0.04 per share)	(2,148)			(2,148)
Treasury stock repurchases	(38,354)							38,354
Stock based compensation expense	$ 10,931		10,931
Stock option exercises (in shares)	281
Stock Issued During Period, Value, Stock Options Exercised	$ 6,907	$ 56	6,851
Stock issued to, acquired for and distributed from rabbi trust (in shares)		30
Stock issued to, acquired for and distributed from rabbi trust	(355)	$ 7	(348)			293	(293)
Shares, Issued at Aug. 31, 2024		54,235
Ending Balance at Aug. 31, 2024	391,979	$ 10,847	235,660	261,870	$ (116,398)	$ (3,777)	$ 3,777	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustments to Additional Paid in Capital, Other	3,122		$ 3,122
Treasury Stock, Shares, Retired		(30,082)
Treasury Stock, Retired, Par Value Method, Amount				(6,017)
Treasury Stock, Retired, Cost Method, Amount	0			$ (832,843)				$ (838,860)
Retained earnings	$ 261,870