Investments In Associated Companies - Summarized Financial Results (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Mar. 26, 2023	Mar. 27, 2022	Mar. 26, 2023	Mar. 27, 2022
Schedule of Equity Method Investments [Line Items]
Operating revenue	$ 170,687	$ 190,014	$ 355,818	$ 392,296
Operating expenses	168,501	194,649	344,122	373,571
Restructuring costs	3,694	10,590	4,340	13,790
Depreciation and amortization	7,733	8,951	15,619	18,627
Operating income (loss)	2,858	(3,228)	14,036	21,886
Net income	(5,366)	(6,694)	(3,542)	6,505
Equity in earnings	672	1,407	2,340	3,161
TNI Partners
Schedule of Equity Method Investments [Line Items]
Equity in earnings	569	1,093	1,833	2,351
MNI
Schedule of Equity Method Investments [Line Items]
Equity in earnings	104	314	507	810
TNI Partners
Schedule of Equity Method Investments [Line Items]
Operating revenue	8,169	8,594	16,710	17,575
Operating expenses	6,889	6,409	13,364	12,873
Operating income (loss)	1,280	2,185	3,346	4,702
Net income	1,137	1,093	3,666	2,351
MNI
Schedule of Equity Method Investments [Line Items]
Operating revenue	10,603	11,561	22,507	23,756
Operating expenses	8,681	9,344	18,026	18,720
Restructuring costs	101	0	127	0
Depreciation and amortization	135	170	273	340
Operating income (loss)	1,686	2,047	4,081	4,696
Net income	$ 207	$ 627	$ 1,014	$ 1,620