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. 29, 2018	$ 1,224,986	$ 51,280	$ 502,257	$ 1,974,125	$ (738,494)	$ (118,449)	$ (72,941)	$ (372,792)
Increase (Decrease) in Stockholders' Equity
Issuance of shares			(2,201)		5,796
Equity-based compensation expense			2,008
Adjustment to market - SECT, SERP and other			(14,780)
Net earnings	42,769			42,769
Dividends				(8,703)
Adoption of ASC 606 | ASC 606				14,923
Class A and B shares purchased					(10,541)
Issuance of shares - SECT						8,761
Purchase of shares - SECT	(1,930)					(1,930)
Adjustment to market						9,436	5,344
Other comprehensive income (loss)	(2,604)							(2,604)
End of period at Dec. 29, 2018	1,273,264	51,280	487,284	2,023,114	(743,239)	(102,182)	(67,597)	(375,396)
Beginning of period - Common Stock at Sep. 29, 2018									43,784,489			7,495,224
Increase (Decrease) in Stockholders' Equity
Conversion of Class B to Class A									946			(946)
End of period - Common Stock at Dec. 29, 2018									43,785,435			7,494,278
Beginning of period, Shares at Sep. 29, 2018										(10,872,575)	(425,148)		(3,323,996)	(983,772)	(876,170)
Increase (Decrease) in Stockholders' Equity
Class A and B shares issued related to equity compensation, shares										23,741			58,793
Class A and B shares purchased, shares										(48,573)			(83,296)
Issuance of shares - SECT														107,577
Purchase of shares - SECT														(23,669)
End of period, Shares at Dec. 29, 2018										(10,897,407)	(425,148)		(3,348,499)	(899,864)	(876,170)
Beginning of period at Sep. 28, 2019	1,322,481	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
Adjustment to market - SECT, SERP and other			1,406
Net earnings	50,027			50,027
Dividends				(8,661)
Adoption of ASC 606 | ASC 606				0
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)