Consolidated Condensed Statements of Shareholders' Equity Statement - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock At Cost	Stock Employee Compensation Trust (SECT)	Supplemental Retirement Plan (SERP) Trust	Accumulated Other Comprehensive Loss	Class A Common Stock	Class A Common Stock Treasury Stock At Cost	Class A Common Stock Stock Employee Compensation Trust (SECT)	Class B Common Stock	Class B Common Stock Treasury Stock At Cost	Class B Common Stock Stock Employee Compensation Trust (SECT)	Class B Common Stock Supplemental Retirement Plan (SERP) Trust
Beginning of period at Sep. 28, 2019		$ 51,280	$ 510,546	$ 2,128,739	$ (769,569)	$ (111,492)	$ (71,546)	$ (415,477)
Increase (Decrease) in Stockholders' Equity
Issuance of shares			4,489		527
Equity-based compensation expense			2,381
Adjustments to market - SECT and SERP			1,406
Net earnings	$ 50,027			50,027
Dividends				(8,661)
Class A and B shares purchased					(59,411)
Issuance of shares - SECT						0
Purchase of shares - SECT	(2,440)					(2,440)
Adjustment to market						(1,571)	165
Other comprehensive income (loss)	27,298							27,298
End of period at Dec. 28, 2019	1,336,691	51,280	518,822	2,170,105	(828,453)	(115,503)	(71,381)	(388,179)
Beginning of period - Common Stock at Sep. 28, 2019									43,794,935			7,484,778
Increase (Decrease) in Stockholders' Equity
Conversion of Class B to Class A									1,400			(1,400)
End of period - Common Stock at Dec. 28, 2019									43,796,335			7,483,378
Beginning of period, Shares at Sep. 28, 2019										(11,101,512)	(425,148)		(3,345,489)	(886,300)	(826,170)
Increase (Decrease) in Stockholders' Equity
Class A and B shares issued related to equity compensation, shares										3,078			94,567
Class A and B shares purchased, shares										(669,106)			(9,680)
Issuance of shares - SECT														0
Purchase of shares - SECT														(28,596)
End of period, Shares at Dec. 28, 2019										(11,767,540)	(425,148)		(3,260,602)	(914,896)	(826,170)
Beginning of period at Oct. 03, 2020	1,243,083	51,280	472,645	2,112,734	(990,783)	(64,242)	(53,098)	(285,453)
Increase (Decrease) in Stockholders' Equity
Issuance of shares			3,118		850
Equity-based compensation expense			2,412
Adjustments to market - SECT and SERP			26,863
Net earnings	37,842			37,842
Dividends				(8,010)
Class A and B shares purchased					(10,862)
Issuance of shares - SECT						274
Purchase of shares - SECT	(655)					(655)
Adjustment to market						(13,974)	(12,888)
Other comprehensive income (loss)	35,191							35,191
End of period at Jan. 02, 2021	$ 1,303,244	$ 51,280	$ 505,038	$ 2,142,566	$ (1,000,795)	$ (78,597)	$ (65,986)	$ (250,262)
Beginning of period - Common Stock at Oct. 03, 2020									43,799,229			7,480,484
Increase (Decrease) in Stockholders' Equity
Conversion of Class B to Class A									3,000			(3,000)
End of period - Common Stock at Jan. 02, 2021									43,802,229			7,477,484
Beginning of period, Shares at Oct. 03, 2020										(13,959,998)	(425,148)		(3,344,877)	(557,543)	(826,170)
Increase (Decrease) in Stockholders' Equity
Class A and B shares issued related to equity compensation, shares										14,452			71,059
Class A and B shares purchased, shares										(72,575)			(92,861)
Issuance of shares - SECT														4,135
Purchase of shares - SECT														(8,543)
End of period, Shares at Jan. 02, 2021										(14,018,121)	(425,148)		(3,366,679)	(561,951)	(826,170)