Consolidated Statements Of Changes In Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balance, beginning of year at Aug. 31, 2009	$ 581	$ 248,840	$ (414,995)	$ 676,626	$ (10,223)	$ 500,829
COMMON STOCK
Foreign currency translation adjustments					(10,073)	(10,073)
Net unrealized gain (loss) on cash flow hedges, net of tax					(1,089)	(1,089)
Net income				150,211		150,211
Dividends				(39,993)		(39,993)
Repurchase of common stock			(192,803)			(192,803)
Common stock issued for employee stock plans	20	56,747				56,767
Stock-based compensation expense		14,065				14,065
Tax benefits from share-based payment arrangements		24,492				24,492
Balance, end of year at Aug. 31, 2010	601	344,144	(607,798)	786,844	(21,385)	502,406
COMMON STOCK
Foreign currency translation adjustments					14,897	14,897
Net unrealized gain (loss) on cash flow hedges, net of tax					828	828
Net income				171,046		171,046
Dividends				(45,812)		(45,812)
Repurchase of common stock			(216,584)			(216,584)
Common stock issued for employee stock plans	13	44,290				44,303
Stock-based compensation expense		25,773				25,773
Tax benefits from share-based payment arrangements		18,331				18,331
Balance, end of year at Aug. 31, 2011	614	432,538	(824,382)	912,078	(5,660)	515,188
COMMON STOCK
Foreign currency translation adjustments					(14,925)	(14,925)
Net unrealized gain (loss) on cash flow hedges, net of tax					(2,141)	(2,141)
Net income				188,809		188,809
Dividends				(51,887)		(51,887)
Repurchase of common stock			(153,641)			(153,641)
Common stock issued for employee stock plans	9	33,383				33,392
Stock-based compensation expense		21,982				21,982
Tax benefits from share-based payment arrangements		11,159				11,159
Stock issued for acquisition of business (See Note 7)		(11)	3,985			3,974
Purchase of common stock upon restricted stock vesting (See Note 14)			354			354
Retirement of treasury stock (See Note 12)	(167)	(361,482)	850,935	(489,286)
Balance, end of year at Aug. 31, 2012	$ 456	$ 137,569	$ (122,749)	$ 559,714	$ (22,726)	$ 552,264