Income Per Share - Schedule of Computation of Diluted Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Feb. 29, 2020	Feb. 23, 2019	Feb. 29, 2020	Feb. 23, 2019
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
As reported - Basic	$ 34,680	$ 47,606	$ 82,922	$ 85,926
As reported - Basic (in shares)	18,936	19,138	18,943	19,140
As reported – Diluted	$ 34,680	$ 47,606	$ 82,922	$ 85,926
As reported - Diluted (in shares)	19,105	19,232	19,114	19,258
As reported - Diluted (in dollars per share)	$ 1.82	$ 2.48	$ 4.34	$ 4.46
Common Stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
As reported - Basic	$ 29,129	$ 39,923	$ 69,654	$ 72,061
As reported - Basic (in shares)	15,293	15,428	15,300	15,430
As reported - Basic (in dollars per share)	$ 1.90	$ 2.59	$ 4.55	$ 4.67
Add: effect of dilutive potential common shares	$ 0	$ 0	$ 0	$ 0
Add: effect of dilutive potential common shares (in shares)	169	94	171	118
Class B Common Stock
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
As reported - Basic	$ 5,551	$ 7,683	$ 13,268	$ 13,865
As reported - Basic (in shares)	3,643	3,710	3,643	3,710
As reported - Basic (in dollars per share)	$ 1.52	$ 2.07	$ 3.64	$ 3.74