CONSOLIDATED STATEMENTS OF EQUITY - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Tax Benefit From Stock Based Compensation [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Total
Balance at Aug. 31, 2013	$ 3	$ 390,581	$ 8,016	$ (41,475)	$ 143,871	$ (19,947)	$ 481,049
Balance (in shares) at Aug. 31, 2013	30,924,000					690,000
Purchase of treasury stock						$ (4,773)	(4,773)
Purchase of treasury stock (in shares)						51,000
Issuance of restricted stock award (in shares)	24,000
Forfeiture of restricted stock awards (in shares)	(2,000)
Exercise of stock options (in shares)	5,000
Exercise of stock options		118					118
Stock-based compensation		6,451	1,489				7,940
Dividend paid to stockholders					(21,144)		(21,144)
Net income					92,886		92,886
Other comprehensive income (loss)				(7,811)			(7,811)
Balance at Aug. 31, 2014	$ 3	397,150	9,505	(49,286)	215,613	$ (24,720)	548,265
Balance (in shares) at Aug. 31, 2014	30,951,000					741,000
Purchase of treasury stock						$ (4,677)	(4,677)
Purchase of treasury stock (in shares)						52,000
Issuance of restricted stock award (in shares)	33,000
Forfeiture of restricted stock awards (in shares)	(9,000)
Exercise of stock options (in shares)	3,000
Exercise of stock options		49					49
Stock-based compensation		5,969	1,206				7,175
Dividend paid to stockholders					(21,126)		(21,126)
Net income					89,124		89,124
Other comprehensive income (loss)				(52,226)			(52,226)
Balance at Aug. 31, 2015	$ 3	403,168	10,711	(101,512)	283,611	$ (29,397)	$ 566,584
Balance (in shares) at Aug. 31, 2015	30,978,000					793,000	30,184,584
Purchase of treasury stock						$ (3,334)	$ (3,334)
Purchase of treasury stock (in shares)						43,000
Issuance of restricted stock award (in shares)	256,000
Exercise of stock options (in shares)	4,000
Exercise of stock options		80					80
Stock-based compensation		9,121	610				9,731
Dividend paid to stockholders					(21,274)		(21,274)
Net income					88,723		88,723
Other comprehensive income (loss)				(2,439)			(2,439)
Balance at Aug. 31, 2016	$ 3	$ 412,369	$ 11,321	$ (103,951)	$ 351,060	$ (32,731)	$ 638,071
Balance (in shares) at Aug. 31, 2016	31,238,000					836,000	30,401,307