Note 6 - Net Income Per Share (Details) - Summary of Earnings Per Share Basic 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, Basic, by Common Class, Including Two Class Method [Line Items]
Net income available to shareholders	$ 37,413	$ 34,462
Allocation of net income for Basic	37,413	34,462
Weighted average number of shares for Basic (in Shares)	20,061	20,010
Common Class A [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Allocation of net income for Basic	29,649	27,208
Weighted average number of shares for Basic (in Shares)	15,128	15,029
Earnings per share for Basic (in Dollars per share)	$ 1.96	$ 1.81
Common Class B [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Allocation of net income for Basic	7,434	6,798
Weighted average number of shares for Basic (in Shares)	4,741	4,693
Earnings per share for Basic (in Dollars per share)	$ 1.57	$ 1.45
Unvested Participating Shares [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Allocation of net income for Basic	$ 330	$ 456
Weighted average number of shares for Basic (in Shares)	192	288