Note 6. Net Income Per Share (Detail) - Summary of Earnings Per Share Diluted 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
As reported - Basic (in Shares)	19,992	19,907	19,973	19,892
Add: Undistributed earnings allocated to unvested participating shares	$ 457	$ 337	$ 989	$ 799
Less: Undistributed earnings reallocated to unvested participating shares	(433)	(320)	(937)	(759)
Common Class A [Member]
As reported - Basic	20,963	15,081	45,155	35,341
As reported - Basic (in Shares)	14,962	14,873	14,943	14,856
As reported - Basic (in Dollars per share)	$ 1.40	$ 1.01	$ 3.02	$ 2.38
Effect of dilutive potential common shares (in Shares)	138	92	124	79
Diluted EPS – Common Stock	26,196	18,863	56,440	44,213
Diluted EPS – Common Stock (in Shares)	19,747	19,605	19,714	19,575
Diluted EPS – Common Stock (in Dollars per share)	$ 1.33	$ 0.96	$ 2.86	$ 2.26
Common Class B [Member]
As reported - Basic	5,209	3,765	11,233	8,832
As reported - Basic (in Shares)	4,647	4,640	4,647	4,640
As reported - Basic (in Dollars per share)	$ 1.12	$ 0.81	$ 2.42	$ 1.90
Effect of dilutive potential common shares	$ 5,209	$ 3,765	$ 11,233	$ 8,832
Effect of dilutive potential common shares (in Shares)	4,647	4,640	4,647	4,640