Note 1 - Summary of Significant Accounting Policies (Details) - Summary of Earnings Per Share, Basic, Two Class Method (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Aug. 31, 2013	Aug. 25, 2012	Aug. 27, 2011
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income available to shareholders (in Dollars)	$ 116,685	$ 94,989	$ 76,486
Common Class A [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income available to shareholders (in Dollars)	91,916	74,643	59,944
Allocation of net income for Basic:
Allocation of net income for Basic:	$ 91,916	$ 74,643	$ 59,944
Weighted average number of shares for Basic:
Weighted average number of shares for Basic (in Shares)	14,975	14,882	14,791
Earnings per share for Basic:
Earnings per share for Basic	$ 6.14	$ 5.02	$ 4.05
Common Class B [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income available to shareholders (in Dollars)	22,913	18,630	15,104
Allocation of net income for Basic:
Allocation of net income for Basic:	$ 22,913	$ 18,630	$ 15,104
Weighted average number of shares for Basic:
Weighted average number of shares for Basic (in Shares)	4,666	4,643	4,658
Earnings per share for Basic:
Earnings per share for Basic	$ 4.91	$ 4.01	$ 3.24
Unvested Participating Shares [Member]
Allocation of net income for Basic:
Allocation of net income for Basic:	$ 1,856	$ 1,716	$ 1,438
Weighted average number of shares for Basic:
Weighted average number of shares for Basic (in Shares)	345	391	405
Total Allocation Of Net Income Basic [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income available to shareholders (in Dollars)	$ 116,685	$ 94,989	$ 76,486
Total Weighted Average Number Of Shares Basic [Member]
Weighted average number of shares for Basic:
Weighted average number of shares for Basic (in Shares)	19,986	19,916	19,854