Summary of Significant Accounting Policies - Property, Plant and Equipment Narrative (Details) - USD ($)			3 Months Ended	12 Months Ended
	Oct. 15, 2020	Sep. 28, 2020	Apr. 01, 2023	Sep. 28, 2024	Sep. 30, 2023	Sep. 24, 2022
Accounting Policies [Abstract]
Grants received from Department of Defense	$ 119,300,000	$ 7,600,000
Proceeds from the Department of Defense			$ 20,500,000	$ 0	$ 20,500,000	$ 75,000,000.0
Department of Defense funds received						75,000,000
Department of Defense funds received, not capitalized						$ 7,600,000