Note 7 - Net Income Per Share (Details) - Summary of Earnings Per Share, Diluted, Two Class Method - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	May. 30, 2015	May. 31, 2014	May. 30, 2015	May. 31, 2014
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
As reported - Basic	$ 32,499	$ 30,944	$ 95,358	$ 91,053
Add: effect of dilutive potential common shares
Add: Undistributed earnings allocated to unvested participating shares	194	317	737	1,095
Less: Undistributed earnings reallocated tounvested participating shares	(184)	(300)	(697)	(1,036)
Diluted EPS – Common Stock	$ 32,310	$ 30,637	$ 94,644	$ 89,992
Diluted EPS – Common Stock (in Shares)	20,118	19,977	20,057	19,921
Diluted EPS – Common Stock (in Dollars per share)	$ 1.61	$ 1.53	$ 4.72	$ 4.52
Common Class A [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
As reported - Basic	$ 25,817	$ 24,493	$ 75,650	$ 71,971
As reported - Basic (in Shares)	15,207	15,102	15,173	15,069
As reported - Basic (in Dollars per share)	$ 1.70	$ 1.62	$ 4.99	$ 4.78
Add: effect of dilutive potential common shares
Dilutive potential common shares (in Shares)	138	153	132	151
Diluted EPS – Common Stock	$ 32,310	$ 30,637	$ 94,644	$ 89,992
Diluted EPS – Common Stock (in Shares)	20,118	19,977	20,057	19,921
Diluted EPS – Common Stock (in Dollars per share)	$ 1.61	$ 1.53	$ 4.72	$ 4.52
Common Class B [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
As reported - Basic	$ 6,483	$ 6,127	$ 18,954	$ 17,962
As reported - Basic (in Shares)	4,773	4,722	4,752	4,701
As reported - Basic (in Dollars per share)	$ 1.36	$ 1.30	$ 3.99	$ 3.82
Add: effect of dilutive potential common shares
Dilutive potential common shares	$ 6,483	$ 6,127	$ 18,954	$ 17,962
Dilutive potential common shares (in Shares)	4,773	4,722	4,752	4,701