CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Tax benefit from stock-based compensation [Member]	Accumulated other comprehensive loss [Member]	Retained Earnings (Accumulated deficit) [Member]	Treasury Stock [Member]
Balance at Aug. 31, 2012	$ 418,914	$ 3	$ 384,154	$ 6,680	$ (33,182)	$ 77,739	$ (16,480)
Balance (in shares) at Aug. 31, 2012		30,856,000					645,000
Treasury Stock, Shares, Acquired							42,000
Treasury Stock, Value, Acquired, Cost Method	(3,286)						(3,286)
Issuance of treasury stock (in shares)	0
Issuance of restricted stock award (in shares)		61,000
Forfeiture of restricted stock awards (in shares)		(2,000)
Exercise of stock options (in shares)		6,000
Proceeds from Stock Options Exercised	125		125
Stock-based compensation	6,125		4,854	1,271
Payments of Dividends	(9,065)					(9,065)
Dividends payable to stockholders	(9,065)					(9,065)
Net income	63,426					63,426
Other Comprehensive Income (Loss)	(3,474)				(3,474)
Balance at May. 31, 2013	463,700	3	389,133	7,951	(36,656)	123,035	(19,766)
Balance (in shares) at May. 31, 2013		30,921,000					687,000
Balance at Aug. 31, 2012					(33,182)
Other Comprehensive Income (Loss)					(8,293)
Balance at Aug. 31, 2013	481,049	3	390,581	8,016	(41,475)	143,871	(19,947)
Balance (in shares) at Aug. 31, 2013		30,924,000					690,000
Treasury Stock, Shares, Acquired							49,000
Treasury Stock, Value, Acquired, Cost Method	(4,601)						(4,601)
Issuance of treasury stock (in shares)	0
Issuance of restricted stock award (in shares)		20,000
Forfeiture of restricted stock awards (in shares)		(1,000)
Exercise of stock options (in shares)		5,000
Proceeds from Stock Options Exercised	118		118
Stock-based compensation	6,343		4,870	1,473
Payments of Dividends	(10,570)					(10,570)
Dividends payable to stockholders	(10,593)					(10,593)
Net income	71,030					71,030
Other Comprehensive Income (Loss)	(8,848)				(8,848)
Balance at May. 31, 2014	$ 523,928	$ 3	$ 395,569	$ 9,489	$ (50,323)	$ 193,738	$ (24,548)
Balance (in shares) at May. 31, 2014		30,948,000					739,000