Property, Plant, and Equipment (Narrative) (Details) - USD ($) $ in Thousands				12 Months Ended
	Sep. 25, 2020	Aug. 11, 2020	Dec. 30, 2019	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Property, Plant and Equipment [Line Items]
Net gain (loss) on sales of assets				$ 4,452	$ 23,598	$ (1,925)
Impairment of assets held for sale					37,902
Duarte Facility [Member]
Property, Plant and Equipment [Line Items]
Net gain (loss) on sales of assets		$ 8,801	$ 13,522		22,323
Disposal Groups [Member]
Property, Plant and Equipment [Line Items]
Impairment of assets held for sale					37,902
Disposal Groups [Member] | Plant, Property and Equipment [Member]
Property, Plant and Equipment [Line Items]
Impairment of assets held for sale					$ 13,421
Loveland Facility [Member]
Property, Plant and Equipment [Line Items]
Net gain (loss) on sales of assets	$ 2,330