Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Jun. 26, 2020	Sep. 30, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 529,656	$ 520,533
Accumulated depreciation	(287,002)	(259,830)
Property, plant and equipment, net	242,654	260,703
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment	20,150	19,897
Buildings and related improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment	128,702	127,061
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment	324,097	318,421
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment	9,126	9,055
Software
Property, Plant and Equipment [Line Items]
Property, plant and equipment	26,027	24,835
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 21,554	$ 21,264