Revenue and Contract Balances - Summary of Contract Liabilities/Assets (Details) - USD ($) $ in Thousands	Mar. 28, 2021	Sep. 27, 2020
Revenue from Contract with Customer [Abstract]
Contract assets	$ 95,079	$ 92,632
Contract liabilities	(185,602)	(171,905)
Net contract liabilities	(90,523)	(79,273)
Disaggregation of Revenue [Line Items]
Contract assets	95,079	92,632
Contract Retentions
Revenue from Contract with Customer [Abstract]
Contract assets	7,400	12,300
Disaggregation of Revenue [Line Items]
Contract assets	$ 7,400	$ 12,300