Note 6. Net Income Per Share (Detail) - Summary of Earnings Per Share Basic Two Class Method (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Feb. 23, 2013	Feb. 25, 2012	Feb. 23, 2013	Feb. 25, 2012
Net income	$ 26,642	$ 19,196	$ 57,402	$ 44,998
Weighted average number of shares for Basic:
Weighted average number of shares for Basic (in Shares)	19,992	19,907	19,973	19,892
Common Class A [Member]
Net income	20,963	15,081	45,155	35,341
Weighted average number of shares for Basic:
Weighted average number of shares for Basic (in Shares)	14,962	14,873	14,943	14,856
Earnings per share for Basic:
Earnings per share for Basic (in Dollars per share)	$ 1.40	$ 1.01	$ 3.02	$ 2.38
Common Class B [Member]
Net income	5,209	3,765	11,233	8,832
Weighted average number of shares for Basic:
Weighted average number of shares for Basic (in Shares)	4,647	4,640	4,647	4,640
Earnings per share for Basic:
Earnings per share for Basic (in Dollars per share)	$ 1.12	$ 0.81	$ 2.42	$ 1.90
Unvested Participating Shares [Member]
Net income	$ 470	$ 350	$ 1,014	$ 825
Weighted average number of shares for Basic:
Weighted average number of shares for Basic (in Shares)	383	394	383	396