Joint Ventures (Details) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 28, 2026	Mar. 29, 2025	Mar. 28, 2026	Mar. 29, 2025	Apr. 01, 2026	Sep. 27, 2025
Schedule of Equity Method Investments [Line Items]
Equity in net income of consolidated affiliates	$ 1,800,000	$ 2,000,000.0	$ 4,000,000.0	$ 4,100,000
Equity in net income of non-consolidated affiliates	1,823,000	1,575,000	3,817,000	3,379,000
Equity investment in affiliates	$ 39,204,000		39,204,000			$ 35,197,000
Equity investment in affiliates (Note 11)			$ 190,000	500,000
Micro Bird Holdings Inc.
Schedule of Equity Method Investments [Line Items]
Equity interest in equity method investment (as a percent)	50.00%		50.00%
Equity investment in affiliates	$ 39,200,000		$ 39,200,000			35,200,000
Micro Bird Holdings Inc. | Subsequent event
Schedule of Equity Method Investments [Line Items]
Remaining ownership percentage acquired					50.00%
Clean Bus Solutions (CBS)
Schedule of Equity Method Investments [Line Items]
Equity interest in equity method investment (as a percent)	50.00%		50.00%
Equity in net income of non-consolidated affiliates	$ (100,000)	$ (400,000)	$ (200,000)	(700,000)
Dividends			0	0
Equity investment in affiliates						0
Equity investment in affiliates (Note 11)	200,000			$ 500,000
Non-cash impairment charge	7,400,000
Carrying value of investment	$ 0		$ 0			$ 0