Note 1 - Summary of Earnings Per Share, Diluted, Two Class Method (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended									12 Months Ended
	Aug. 27, 2016	[1]	May 28, 2016	Feb. 27, 2016	Nov. 28, 2015	Aug. 29, 2015	May 30, 2015	Feb. 28, 2015	Nov. 29, 2014	Aug. 27, 2016	Aug. 29, 2015	Aug. 30, 2014
Common Class A [Member]
Allocation of net income for Basic	$ 28,097		$ 23,939	$ 18,691	$ 28,539	$ 23,011	$ 25,817	$ 20,182	$ 29,649	$ 99,282	$ 98,665	$ 94,849
As reported - Basic (in shares)	15,268		15,253	15,241	15,218	15,210	15,207	15,185	15,128	15,245	15,182	15,080
Earnings per share for Basic (in dollars per share)	$ 1.84		$ 1.57	$ 1.23	$ 1.88	$ 1.51	$ 1.70	$ 1.33	$ 1.96	$ 6.51	$ 6.50	$ 6.29
Add: effect of dilutive potential common shares
Add: effect of dilutive potential common shares (in shares)										93	134	148
Diluted EPS – Common Stock	$ 35,250		$ 30,007	$ 23,401	$ 35,741	$ 28,821	$ 32,310	$ 25,235	$ 37,101	$ 124,409	$ 123,472	$ 118,626
Diluted EPS – Common Stock (in shares)	20,223		20,183	20,138	20,132	20,142	20,118	20,065	20,008	20,154	20,079	19,939
Diluted EPS – Common Stock (in dollars per share)	$ 1.74		$ 1.49	$ 1.16	$ 1.78	$ 1.43	$ 1.61	$ 1.26	$ 1.85	$ 6.17	$ 6.15	$ 5.95
Common Class B [Member]
Allocation of net income for Basic	$ 7,139		$ 6,061	$ 4,704	$ 7,193	$ 5,803	$ 6,483	$ 5,041	$ 7,434	$ 25,093	$ 24,761	$ 23,705
As reported - Basic (in shares)	4,850		4,827	4,795	4,795	4,795	4,773	4,741	4,741	4,816	4,763	4,711
Earnings per share for Basic (in dollars per share)	$ 1.47		$ 1.26	$ 0.98	$ 1.50	$ 1.21	$ 1.36	$ 1.06	$ 1.57	$ 5.21	$ 5.20	$ 5.03
Add: effect of dilutive potential common shares										$ 25,093	$ 24,761	$ 23,705
Add: effect of dilutive potential common shares (in shares)										4,816	4,763	4,711
Add: Undistributed earnings allocated to unvested participating shares										$ 636	$ 853	$ 1,339
Less: Undistributed earnings reallocated to unvested participating shares										(602)	(807)	(1,267)
Diluted EPS – Common Stock										$ 124,409	$ 123,472	$ 118,626
Diluted EPS – Common Stock (in shares)										20,154	20,079	19,939
Diluted EPS – Common Stock (in dollars per share)										$ 6.17	$ 6.15	$ 5.95

[1] In the fourth fiscal quarter of 2016, operating results benefited from a settlement of environmental litigation that resulted in the Company recording a $15.9 million pre-tax gain. This gain translated into a $0.48 benefit to the Company's diluted earnings per share.