Net Income Per Share, Schedule of Earnings Per Share, Diluted, Two Class Method (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	May 26, 2012	May 28, 2011	May 26, 2012	May 28, 2011
Common Class A [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income	$ 21,587	$ 14,453	$ 56,926	$ 45,810
Earning per share - basic (in amounts per share)	$ 1.45	$ 0.98	$ 3.83	$ 3.10
Common Stock options (in shares)	97,000	83,000	86,000	82,000
Undistributed earnings allocated to unvested participating shares	478	330	1,279	1,067
Undistributed earnings reallocated to unvested participating shares	(453)	(313)	(1,214)	(1,012)
Diluted EPS - Common Stock	26,993	18,105	71,205	57,420
Diluted EPS - Common Stock (in dollars per share)	$ 1.37	$ 0.93	$ 3.63	$ 2.94
Common stock excluded from the calculation of diluted earnings per share (in shares)	18,056	23,549	19,786	116,852
Diluted EPS - Common Stock (in shares)	19,646,000	19,549,000	19,600,000	19,522,000
Common Class B [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income	$ 5,381	$ 3,635	$ 14,214	$ 11,555
Earning per share - basic (in amounts per share)	$ 1.16	$ 0.78	$ 3.06	$ 2.48
Common Stock options (in shares)	4,644,000	4,656,000	4,642,000	4,660,000