Property Plant and Equipment - Components of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Apr. 03, 2020	Sep. 27, 2019
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 283,093	$ 281,834
Less accumulated depreciation and amortization	(157,328)	(149,187)
Property and equipment, net	125,765	132,647
Construction in process
Property, Plant and Equipment [Line Items]
Total property and equipment	14,067	24,848
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	191,660	175,696
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	19,241	12,962
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	3,736	3,716
Computer equipment and software
Property, Plant and Equipment [Line Items]
Total property and equipment	18,277	18,116
Assets Held under Capital Leases [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	0	46,496
Less accumulated depreciation and amortization		(5,300)
Assets Held Under Finance Leases [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 36,112	$ 0