Condensed Consolidated Statement Of Shareholders' Equity (USD $) In Thousands	Class A Common Stock [Member] Common Stock [Member]	Class A Common Stock [Member] Retained Earnings [Member]	Class A Common Stock [Member]	Class B Common Stock [Member] Common Stock [Member]	Class B Common Stock [Member] Retained Earnings [Member]	Class B Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Class A Treasury Stock [Member]	Total
Balance, Value at Aug. 31, 2013	$ 55			$ 14			$ 528,770	$ 1,132,868	$ (4,427)	$ (266,897)	$ 1,390,383
Balance, Shares at Aug. 31, 2013	54,634			14,141						5,341
Exchange of Class B common stock for Class A common stock, Shares	720			(720)
Exchange of Class B common stock for Class A common stock, Value	1			(1)
Exercise of common stock options, including income tax benefits of $4,740, Shares	343										343
Exercise of common stock options, including income tax benefits of $4,740, Value							22,305				22,305
Common stock issued under associate stock purchase plan, Shares										(39)
Common stock issued under associate stock purchase plan, Value							1,449			1,473	2,922
Issuance of restricted common stock, net of cancellations, Shares	105
Stock-based compensation							13,020				13,020
Purchase of treasury stock, Shares										1,505
Purchase of treasury stock, Value										(115,606)	(115,606)
Cash dividends paid on common stock		(48,225)	(48,225)		(13,785)	(13,785)
Issuance of dividend equivalent units							195	(195)
Foreign currency translation adjustments									(319)		(319)
Net income								173,254			173,254
Balance, Value at May. 31, 2014	$ 56			$ 13			$ 565,739	$ 1,243,917	$ (4,746)	$ (381,030)	$ 1,423,949
Balance, Shares at May. 31, 2014	55,802			13,421						6,807