Shareholders' Equity (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
	Mar. 15, 2022	Feb. 26, 2022	Feb. 27, 2021	Feb. 26, 2022	Feb. 27, 2021
Components Of Shareholders Equity [Line Items]
Stock Issued During Period, Shares, Employee Stock Ownership Plan		16,000	16,000	30,000	31,000
Cash dividends paid per common share				$ 1.50	$ 1.50
Cash dividends paid				$ 83,586	$ 83,685
Special Cash Dividend [Member]
Components Of Shareholders Equity [Line Items]
Cash dividends paid per common share					$ 3.50
Cash dividends paid					$ 195,351
Subsequent Event [Member]
Components Of Shareholders Equity [Line Items]
Dividends declared date	Mar. 22, 2022
Dividends payable per share	$ 0.75
Dividend payable date	Apr. 26, 2022
Dividends date of record	Apr. 12, 2022
Dividend payable amount	$ 41,881
Class A Common Stock [Member]
Components Of Shareholders Equity [Line Items]
Common stock shares repurchased		4,000	4,000	57,000	50,000
Purchase of treasury stock		$ 254	$ 360	$ 4,813	$ 3,519
Class A Common Stock [Member] | Share Repurchase Program [Member]
Components Of Shareholders Equity [Line Items]
Number of shares authorized for repurchase		5,000		5,000
Maximum number of shares that can be repurchased		5,000		5,000
Treasury Stock [Member] | Class A Common Stock [Member]
Components Of Shareholders Equity [Line Items]
Purchase of treasury stock		$ 254	$ 360	$ 4,813	$ 3,519