Commitments and Contingencies - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 27, 2020	Mar. 27, 2020	Mar. 29, 2019	Sep. 30, 2019
Loss Contingencies [Line Items]
Purchase obligations for rest of fiscal year	$ 167,507	$ 167,507
Purchase obligations for year two	4,722	4,722
Total settlement for prior cap agreement deductible	13,000	13,000
Insurance deductible expense	1,000
Loss on disposal of property, plant and equipment		4,560	$ 0
Insurance recoveries		3,560
Minimum
Loss Contingencies [Line Items]
Probable losses	4,560	4,560
Maximum
Loss Contingencies [Line Items]
Probable losses	13,000	13,000
Special Products Claims and Other Product Liabilities
Loss Contingencies [Line Items]
Product liability	746	746		$ 2,424
Special Products Claims and Other Product Liabilities | Minimum
Loss Contingencies [Line Items]
Probable losses	1,000	1,000
Special Products Claims and Other Product Liabilities | Maximum
Loss Contingencies [Line Items]
Probable losses	8,000	8,000
Special Products Claims
Loss Contingencies [Line Items]
Total settlement for cap agreement deductible	$ 12,000	$ 12,000