Consolidated Statements Of Stockholders’ Equity (Deficit) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Paid-In Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]
Stockholders' equity (deficit), beginning balance at Aug. 31, 2014	$ 62,675	$ 1,183	$ 225,004	$ 801,202	$ (964,714)
Balance, shares (in shares) at Aug. 31, 2014					64,505
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	64,485			64,485
Cash dividends	(13,972)			(13,972)
Stock-based compensation expense	3,520		3,520
Purchase of treasury stock	(123,786)				$ (123,786)
Purchase of treasury stock, shares (in shares)					4,201
Exercise of stock options and issuance of restricted stock	18,732		(1,458)		$ 20,190
Exercise of stock options and issuance of restricted stock, shares (in shares)					(1,438)
Other	5,779		5,484		$ 295
Other, shares (in shares)					(19)
Stockholders' equity (deficit), ending balance at Aug. 31, 2015	17,433	1,183	232,550	851,715	$ (1,068,015)
Balance, shares (in shares) at Aug. 31, 2015					67,249
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	64,067			64,067
Cash dividends	(21,340)			(21,340)
Stock-based compensation expense	3,766		3,766
Purchase of treasury stock	(148,345)				$ (148,345)
Purchase of treasury stock, shares (in shares)					5,209
Exercise of stock options and issuance of restricted stock	3,842		(5,941)		$ 9,783
Exercise of stock options and issuance of restricted stock, shares (in shares)					(767)
Other	4,934		4,581		$ 353
Other, shares (in shares)					(21)
Stockholders' equity (deficit), ending balance at Aug. 31, 2016	$ (75,643)	1,183	234,956	894,442	$ (1,206,224)
Balance, shares (in shares) at Aug. 31, 2016	71,670				71,670
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 63,663			63,663
Cash dividends	(24,088)			(24,088)
Stock-based compensation expense	3,942		3,942
Purchase of treasury stock	(172,913)				$ (172,913)
Purchase of treasury stock, shares (in shares)					6,726
Exercise of stock options and issuance of restricted stock	2,682		(2,203)		$ 4,885
Exercise of stock options and issuance of restricted stock, shares (in shares)					(293)
Other	599		200		$ 399
Other, shares (in shares)					(22)
Stockholders' equity (deficit), ending balance at Aug. 31, 2017	$ (201,758)	$ 1,183	$ 236,895	$ 934,017	$ (1,373,853)
Balance, shares (in shares) at Aug. 31, 2017	78,081				78,081