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
	Nov. 24, 2012	Nov. 26, 2011
Common Class A [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income	$ 24,191	$ 20,258
Earning per share - basic (in amounts per share)	$ 1.62	$ 1.37
Common Stock options (in shares)	121,000	78,000
Undistributed earnings allocated to unvested participating shares	531	463
Undistributed earnings reallocated to unvested participating shares	(503)	(439)
Diluted EPS - Common Stock	30,244	25,350
Diluted EPS - Common Stock (in dollars per share)	$ 1.54	$ 1.30
Common stock excluded from the calculation of diluted earnings per share (in shares)	0	18,014
Diluted EPS - Common Stock (in shares)	19,693,000	19,557,000
Common Class B [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income	$ 6,025	$ 5,068
Earning per share - basic (in amounts per share)	$ 1.30	$ 1.09
Common Stock options (in shares)	4,647,000	4,641,000