Note 6 - Net Income Per Share (Details) - Summary of Earnings Per Share Diluted Two Class Method (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Nov. 29, 2014	Nov. 30, 2013
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
As reported - Basic	$ 37,413	$ 34,462
Add: Undistributed earnings allocated to unvested participating shares	323	447
Less: Undistributed earnings reallocated to unvested participating shares	(305)	(422)
Diluted EPS – Common Stock	37,101	34,031
Diluted EPS – Common Stock (in Shares)	20,008	19,891
Diluted EPS – Common Stock (in Dollars per share)	$ 1.85	$ 1.71
Common Class A [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
As reported - Basic	29,649	27,208
As reported - Basic (in Shares)	15,128	15,029
As reported - Basic (in Dollars per share)	$ 1.96	$ 1.81
Effect of dilutive potential common shares (in Shares)	139	169
Diluted EPS – Common Stock	37,101	34,031
Diluted EPS – Common Stock (in Shares)	20,008	19,891
Diluted EPS – Common Stock (in Dollars per share)	$ 1.85	$ 1.71
Common Class B [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
As reported - Basic	7,434	6,798
As reported - Basic (in Shares)	4,741	4,693
As reported - Basic (in Dollars per share)	$ 1.57	$ 1.45
Effect of dilutive potential common shares	$ 7,434	$ 6,798
Effect of dilutive potential common shares (in Shares)	4,741	4,693