Consolidated Statements Of Stockholders’ Equity (USD $) In Thousands	Common Stock [Member]	Paid-In Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Total
Stockholders' Equity, Beginning Balance at Aug. 31, 2011	$ 1,183	$ 229,399	$ 687,431	$ (866,317)	$ 51,696
Balance, Shares at Aug. 31, 2011				56,316
Net income			36,085		36,085
Stock-based compensation expense		4,295			4,295
Purchase of treasury stock				(31,102)	(31,102)
Purchase of treasury stock, shares				4,157
Exercise of stock options and issuance of restricted stock		(820)	(529)	1,629	280
Exercise of stock options and issuance of restricted stock, Shares				(108)
Other		(2,331)	(373)	697	(2,007)
Other, shares				(40)
Stockholders' Equity, Ending Balance at Aug. 31, 2012	1,183	230,543	722,614	(895,093)	59,247
Balance, Shares at Aug. 31, 2012				60,325
Net income			36,701		36,701
Stock-based compensation expense		3,630			3,630
Purchase of treasury stock				(35,480)	(35,480)
Purchase of treasury stock, shares				3,332
Exercise of stock options and issuance of restricted stock		(6,127)	(1,057)	23,527	16,343
Exercise of stock options and issuance of restricted stock, Shares				(1,607)
Other		(3,278)	(120)	421	(2,977)
Other, shares				(25)
Stockholders' Equity, Ending Balance at Aug. 31, 2013	1,183	224,768	758,138	(906,625)	77,464
Balance, Shares at Aug. 31, 2013				62,025	62,025
Net income			47,916		47,916
Cash dividends declared per common share			(4,852)		(4,852)
Stock-based compensation expense		3,742			3,742
Purchase of treasury stock				(80,045)	(80,045)
Purchase of treasury stock, shares				4,080
Exercise of stock options and issuance of restricted stock		(4,186)		21,593	17,407
Exercise of stock options and issuance of restricted stock, Shares				(1,575)
Other		680		363	1,043
Other, shares				(25)
Stockholders' Equity, Ending Balance at Aug. 31, 2014	$ 1,183	$ 225,004	$ 801,202	$ (964,714)	$ 62,675
Balance, Shares at Aug. 31, 2014				64,505	64,505