Consolidated Statements of Changes in Stockholders' Equity (USD $) In Thousands	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, 2011	$ 614	$ 432,538	$ (824,382)	$ 912,078	$ (5,660)	$ 515,188
Foreign currency translation adjustments					(14,925)	(14,925)
Net unrealized gain (loss) on cash flow hedges, net of tax					(2,141)	(2,141)	[1]
Net income				188,809		188,809
Dividends				(51,887)		(51,887)
Repurchase of common stock, including stock swaps			(152,933)			(152,933)
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		(11)	3,985			3,974
Purchase of common stock upon restricted stock vesting			(354)			(354)
Retirement of treasury stock	(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
Foreign currency translation adjustments					(5,151)	(5,151)
Net unrealized gain (loss) on cash flow hedges, net of tax					(3,296)	(3,296)	[1]
Net income				198,637		198,637
Dividends				(57,832)		(57,832)
Repurchase of common stock, including stock swaps			(327,454)			(327,454)
Common stock issued for employee stock plans	25	124,124				124,149
Stock-based compensation expense		39,951				39,951
Tax benefits from share-based payment arrangements		25,225				25,225
Stock issued for acquisition of business		0	0			0
Purchase of common stock upon restricted stock vesting			(4,714)			(4,714)
Retirement of treasury stock	0	0	0	0
Balance, end of year at Aug. 31, 2013	481	326,869	(454,917)	700,519	(31,173)	541,779
Foreign currency translation adjustments					7,895	7,895
Net unrealized gain (loss) on cash flow hedges, net of tax					5,357	5,357	[1]
Net income				211,543		211,543
Dividends				(62,558)		(62,558)
Repurchase of common stock, including stock swaps			(275,415)			(275,415)
Common stock issued for employee stock plans	10	52,039				52,039
Stock-based compensation expense		22,891				22,891
Tax benefits from share-based payment arrangements		11,955				11,955
Stock issued for acquisition of business		0	0			0
Purchase of common stock upon restricted stock vesting			(4,414)			(4,414)
Retirement of treasury stock	0	0	0	0
Balance, end of year at Aug. 31, 2014	$ 491	$ 413,754	$ (734,746)	$ 849,504	$ (17,921)	$ 511,082

[1] The unrealized gain (loss) on cash flow hedges disclosed above was net of tax (expense) benefit of ($3,193), $1,965, and $1,283 for the fiscal years ended August 31, 2014, 2013 and 2012, respectively.