Summary of Significant Accounting Policies, Schedule of Earnings Per Share, Diluted, Two Class Method (Details) (USD $) In Thousands, except Per Share data	3 Months Ended								12 Months Ended
	Aug. 27, 2011	May 28, 2011	Feb. 26, 2011	Nov. 27, 2010	Aug. 28, 2010	May 29, 2010	Feb. 27, 2010	Nov. 28, 2009	Aug. 27, 2011	Aug. 28, 2010	Aug. 29, 2009
Earnings Per Share, Diluted [Abstract]
Undistributed earnings allocated to unvested participating shares									$ 1,385	$ 598
Undistributed earnings reallocated to unvested participating shares									(1,315)	(567)
Diluted EPS - Common Stock									75,118	75,827	75,852
Common Stock options (in shares)									83	65	44
Diluted EPS - Common Stock (in shares)									19,532	19,458	19,373
Earning per share - basic (in amounts per share)									$ 4.05	$ 4.11	$ 4.14
Diluted EPS - Common Stock (in dollars per share)									$ 3.85	$ 3.90	$ 3.92
Common Stock [Member]
Earnings Per Share, Diluted [Abstract]
Net Income									59,944	59,921	59,526
Diluted EPS - Common Stock (in shares)									14,791	14,570	14,394
Earning per share - basic (in amounts per share)									$ 4.05	$ 4.11
Common Class B [Member]
Earnings Per Share, Diluted [Abstract]
Net Income	$ 3,549	$ 3,635	$ 3,218	$ 4,704	$ 3,424	$ 3,949	$ 3,476	$ 5,060	$ 15,104	$ 15,875	$ 16,326
Diluted EPS - Common Stock (in shares)									4,658	4,823	4,935
Earning per share - basic (in amounts per share)	$ 0.76	$ 0.78	$ 0.69	$ 1.01	$ 0.73	$ 0.83	$ 0.71	$ 1.03	$ 3.24	$ 3.29	$ 3.31