CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Tax benefit from stock-based compensation [Member]	Accumulated other comprehensive loss [Member]	Retained Earnings [Member]	Treasury Stock [Member]
Balance at Aug. 31, 2014	$ 548,265	$ 3	$ 397,150	$ 9,505	$ (49,286)	$ 215,613	$ (24,720)
Balance (in shares) at Aug. 31, 2014		30,951,000					741,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock (in shares)		0
Stock-based compensation	1,556		1,556	0
Net income	20,647					20,647
Other Comprehensive Income (Loss)	(9,419)				(9,419)
Balance at Nov. 30, 2014	561,049	$ 3	398,706	9,505	(58,705)	236,260	$ (24,720)
Balance (in shares) at Nov. 30, 2014		30,951,000					741,000
Balance at Aug. 31, 2015	566,584	$ 3	403,168	10,711	(101,512)	283,611	$ (29,397)
Balance (in shares) at Aug. 31, 2015		30,978,000					793,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of restricted stock (in shares)		186,000
Stock-based compensation	2,100		2,100	0
Net income	23,672					23,672
Other Comprehensive Income (Loss)	(596)				(596)
Balance at Nov. 30, 2015	$ 591,760	$ 3	$ 405,268	$ 10,711	$ (102,108)	$ 307,283	$ (29,397)
Balance (in shares) at Nov. 30, 2015		31,164,000					793,000