Note 7 - Summary of Earnings Per Share, Basic, Two Class Method (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Feb. 27, 2016	Feb. 28, 2015	Feb. 27, 2016	Feb. 28, 2015
Common Class A [Member]
Income allocated to – Basic:
Income allocated to – Basic	$ 18,691	$ 20,182	$ 47,232	$ 49,834
Weighted average number of shares outstanding – Basic:
Weighted average number of shares for Basic (in shares)	15,241	15,185	15,230	15,156
Income per share – Basic:
Income per share – Basic (in dollars per share)	$ 1.23	$ 1.33	$ 3.10	$ 3.29
Common Class B [Member]
Income allocated to – Basic:
Income allocated to – Basic	$ 4,704	$ 5,041	$ 11,896	$ 12,472
Weighted average number of shares outstanding – Basic:
Weighted average number of shares for Basic (in shares)	4,795	4,741	4,795	4,741
Income per share – Basic:
Income per share – Basic (in dollars per share)	$ 0.98	$ 1.06	$ 2.48	$ 2.63
Unvested Participating Shares [Member]
Income allocated to – Basic:
Income allocated to – Basic	$ 103	$ 223	$ 260	$ 553
Weighted average number of shares outstanding – Basic:
Weighted average number of shares for Basic (in shares)	96	192	95	192
Net income	$ 23,498	$ 25,446	$ 59,388	$ 62,859
Income allocated to – Basic	$ 23,498	$ 25,446	$ 59,388	$ 62,859
Weighted average number of shares for Basic (in shares)	20,132	20,118	20,120	20,089