Summary of Significant Accounting Policies, Schedule of Earnings Per Share, Diluted, Two Class Method (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended									12 Months Ended
	Aug. 25, 2012	May 26, 2012		Feb. 25, 2012	Nov. 26, 2011	Aug. 27, 2011	May 28, 2011	Feb. 26, 2011	Nov. 27, 2010	Aug. 25, 2012	Aug. 27, 2011	Aug. 28, 2010
Earnings Per Share, Diluted [Abstract]
Common stock excluded from the calculation of diluted earnings per share (in shares)										0	116,487	118,800
Common Stock [Member]
Earnings Per Share, Diluted [Abstract]
Net Income										$ 74,643	$ 59,944	$ 59,921
Undistributed earnings allocated to unvested participating shares										1,664	1,385	598
Undistributed earnings reallocated to unvested participating shares										(1,579)	(1,315)	(567)
Diluted EPS - Common Stock										93,358	75,118	75,827
Common Stock options (in shares)										91,000	83,000	65,000
Diluted EPS - Common Stock (in shares)										19,616,000	19,532,000	19,458,000
Earning per share - basic (in amounts per share)										$ 5.02	$ 4.05	$ 4.11
Diluted EPS - Common Stock (in dollars per share)										$ 4.76	$ 3.85	$ 3.90
Common Class A [Member]
Earnings Per Share, Diluted [Abstract]
Net Income	17,717	21,587	[1]	15,081	20,258	14,132	14,453	12,750	18,604	74,643	59,944	59,921
Undistributed earnings allocated to unvested participating shares										1,664
Undistributed earnings reallocated to unvested participating shares										(1,579)
Diluted EPS - Common Stock	22,153	26,993	[1]	18,863	25,350	17,698	18,105	15,983	23,330	93,358	75,118	75,827
Common Stock options (in shares)										91,000
Diluted EPS - Common Stock (in shares)	19,664,000	19,646,000		19,605,000	19,557,000	19,559,000	19,549,000	19,528,000	19,487,000	19,616,000	19,532,000	19,458,000
Earning per share - basic (in amounts per share)	$ 1.19	$ 1.45	[1]	$ 1.01	$ 1.37	$ 0.95	$ 0.98	$ 0.86	$ 1.26	$ 5.02	$ 4.05	$ 4.11
Diluted EPS - Common Stock (in dollars per share)	$ 1.13	$ 1.37	[1]	$ 0.96	$ 1.30	$ 0.90	$ 0.93	$ 0.82	$ 1.20	$ 4.76	$ 3.85	$ 3.90
Common Class B [Member]
Earnings Per Share, Diluted [Abstract]
Net Income	$ 4,416	$ 5,381	[1]	$ 3,765	$ 5,068	$ 3,549	$ 3,635	$ 3,218	$ 4,704	$ 18,630	$ 15,104	$ 15,875
Common Stock options (in shares)										4,643,000	4,658,000	4,823,000
Earning per share - basic (in amounts per share)	$ 0.95	$ 1.16	[1]	$ 0.81	$ 1.09	$ 0.76	$ 0.78	$ 0.69	$ 1.01	$ 4.01	$ 3.24	$ 3.29

[1] In the third fiscal quarter of 2012, operating results benefited from a settlement of environmental litigation that resulted in the Company recording a $6.7 million pre-tax gain. This gain translated into a $0.21 benefit to the Company's diluted earnings per share.