Summary of Significant Accounting Policies - Schedule of Computation of Basic Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Aug. 31, 2019	May 25, 2019	Feb. 23, 2019	Nov. 24, 2018	Aug. 25, 2018	May 26, 2018	Feb. 24, 2018	Nov. 25, 2017	Aug. 31, 2019	Aug. 25, 2018	Aug. 26, 2017
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income available to shareholders	$ 45,988	$ 47,220	$ 47,606	$ 38,320	$ 34,952	$ 36,359	$ 58,378	$ 34,206	$ 179,134	$ 163,895	$ 70,196
Allocation of net income for Basic:
Common Stock									$ 179,134	$ 163,895	$ 70,196
Weighted average number of shares for Basic:
Common Stock (in shares)									19,082	19,811	20,284
Common Stock
Allocation of net income for Basic:
Common Stock	$ 38,619	$ 39,563	$ 39,923	$ 32,137	$ 29,312	$ 30,034	$ 46,744	$ 27,384	$ 150,247	$ 133,802	$ 55,903
Weighted average number of shares for Basic:
Common Stock (in shares)	15,340	15,341	15,428	15,432	15,429	15,446	15,481	15,462	15,385	15,454	15,382
Income per share for Basic:
Common Stock (in dollars per share)	$ 2.52	$ 2.58	$ 2.59	$ 2.08	$ 1.90	$ 1.94	$ 3.02	$ 1.77	$ 9.77	$ 8.66	$ 3.63
Class B Common Stock
Allocation of net income for Basic:
Common Stock	$ 7,369	$ 7,657	$ 7,683	$ 6,183	$ 5,640	$ 6,325	$ 11,634	$ 6,822	$ 28,887	$ 30,093	$ 13,915
Weighted average number of shares for Basic:
Common Stock (in shares)	3,659	3,710	3,710	3,710	3,711	4,087	4,816	4,816	3,697	4,357	4,786
Income per share for Basic:
Common Stock (in dollars per share)	$ 2.01	$ 2.06	$ 2.07	$ 1.67	$ 1.52	$ 1.55	$ 2.42	$ 1.42	$ 7.81	$ 6.91	$ 2.91
Unvested participating shares
Allocation of net income for Basic:
Common Stock									$ 0	$ 0	$ 378
Weighted average number of shares for Basic:
Common Stock (in shares)									0	0	116