Summary of Significant Accounting Policies, Schedule of Earnings Per Share, Basic, 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, basic [Abstract]
Net income	$ 18,014	$ 18,431	$ 16,277	$ 23,764	$ 17,292	$ 19,314	$ 16,226	$ 23,576	$ 76,486	$ 76,408	$ 75,852
Weighted average number of shares - basic									19,854	19,564	19,329
Earning per share - basic (in amounts per share)									$ 4.05	$ 4.11	$ 4.14
Common Stock [Member]
Earnings per share, basic [Abstract]
Net income									59,944	59,921	59,526
Weighted average number of shares - basic									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, basic [Abstract]
Net income									15,104	15,875	16,326
Weighted average number of shares - basic	4,653	4,656	4,661	4,663	4,663	4,766	4,931	4,932	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
Unvested Participating Shares [Member]
Earnings per share, basic [Abstract]
Net income									$ 1,438	$ 612	$ 0
Weighted average number of shares - basic									405	171	0