Note 7 - Net Income Per Share (Details) - Summary of Earnings Per Share, Basic, 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, Basic, by Common Class, Including Two Class Method [Line Items]
Net income	$ 32,499	$ 30,944	$ 95,358	$ 91,053
Allocation of net income for Basic:
Allocation of net income for Basic	$ 32,499	$ 30,944	$ 95,358	$ 91,053
Weighted average number of shares for Basic:
Weighted average number of shares for Basic (in Shares)	20,114	20,053	20,098	20,038
Common Class A [Member]
Allocation of net income for Basic:
Allocation of net income for Basic	$ 25,817	$ 24,493	$ 75,650	$ 71,971
Weighted average number of shares for Basic:
Weighted average number of shares for Basic (in Shares)	15,207	15,102	15,173	15,069
Earnings per share for Basic:
Earnings per share for Basic (in Dollars per share)	$ 1.70	$ 1.62	$ 4.99	$ 4.78
Common Class B [Member]
Allocation of net income for Basic:
Allocation of net income for Basic	$ 6,483	$ 6,127	$ 18,954	$ 17,962
Weighted average number of shares for Basic:
Weighted average number of shares for Basic (in Shares)	4,773	4,722	4,752	4,701
Earnings per share for Basic:
Earnings per share for Basic (in Dollars per share)	$ 1.36	$ 1.30	$ 3.99	$ 3.82
Unvested Participating Shares [Member]
Allocation of net income for Basic:
Allocation of net income for Basic	$ 199	$ 324	$ 754	$ 1,120
Weighted average number of shares for Basic:
Weighted average number of shares for Basic (in Shares)	134	229	173	268