Earnings per Share and Shareholders' Equity Share Repurchase (Details) - USD ($) $ in Thousands	3 Months Ended		123 Months Ended
	Nov. 30, 2022	Nov. 30, 2021	Nov. 30, 2021	Aug. 31, 2022	Aug. 31, 2021
Equity [Abstract]
Treasury Stock, Shares	26,558,965			26,558,965
Stock Repurchase Program, Remaining Number of Shares Authorized to be Repurchased	6,240,265
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 334,323	$ 409,806	$ 409,806	$ 318,611	$ 412,198
Net (loss) earnings	7,453	2,788
Other Comprehensive (Loss) Income, Net of Tax	6,024	(10,044)
Stock Issued During Period, Value, Employee Benefit Plan	42	85
Stock Issued During Period, Value, Restricted Stock Award, Gross	0	0
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	2,155	6,147
Stock Value Issued to Acquired For and Distributed From Rabbi Trust	77	$ 25
Retained earnings	974,204			966,751
Treasury Stock, Value	$ 742,844			$ 742,844
Treasury Stock, Value, Acquired, Cost Method			$ 742,800
Stock Repurchase Program, Number of Shares Authorized to be Repurchased	10,000,000
Common Stock [Member]
Stock Issued During Period, Shares, New Issues	83,529,000	83,092,000	83,092,000	83,397,000	83,022,000
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 16,706	$ 16,622	$ 16,622	$ 16,679	$ 16,604
Stock Issued During Period, Shares, Employee Benefit Plan	3,000	2,000
Stock Issued During Period, Value, Employee Benefit Plan	$ 1	$ 1
Stock Issued During Period, Shares, Restricted Stock Award, Gross	84,000	67,000
Stock Issued During Period, Value, Restricted Stock Award, Gross	$ 17	$ 17
Stock Issued To Acquired For And Distributed From Rabbi Trust	3,000	1,000
Stock Value Issued to Acquired For and Distributed From Rabbi Trust	$ 1	$ 0
Additional Paid-in Capital [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	215,194	207,817	207,817	212,986	202,971
Stock Issued During Period, Value, Employee Benefit Plan	41	84
Stock Issued During Period, Value, Restricted Stock Award, Gross	(17)	(17)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	2,155	6,147
Stock Value Issued to Acquired For and Distributed From Rabbi Trust	76	25
Treasury Stock [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	(742,844)	(667,732)	(667,732)	(742,844)	(667,732)
Retained Earnings [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	974,204	956,127	956,127	966,751	953,339
Net (loss) earnings	7,453	2,788
AOCI Attributable to Parent [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	(128,937)	(103,028)	(103,028)	(134,961)	(92,984)
Other Comprehensive (Loss) Income, Net of Tax	6,024	(10,044)
Stock held in trust [member] [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	(3,239)	(3,092)	(3,092)	(3,209)	(3,067)
Stock Value Issued to Acquired For and Distributed From Rabbi Trust	(30)	(25)
Deferred Compensation, Share-based Payments [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	3,239	3,092	$ 3,092	$ 3,209	$ 3,067
Stock Value Issued to Acquired For and Distributed From Rabbi Trust	$ 30	$ 25