Restructurings - Summary of Costs Related to Restructuring Actions (Detail) - USD ($)	12 Months Ended
	Oct. 02, 2020	Sep. 27, 2019	Sep. 28, 2018
Restructuring Reserve [Roll Forward]
Beginning balance	$ 2,527,000	$ 89,000	$ 627,000
Restructuring cost	1,139,000	19,543,000	6,265,000
Charges paid/settled	(3,405,000)	(17,105,000)	(6,803,000)
Ending balance	261,000	2,527,000	89,000
2019 Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	1,993,000	0
Restructuring cost	1,197,000	11,565,000
Charges paid/settled	(2,929,000)	(9,572,000)
Ending balance	261,000	1,993,000	0
Design Facility Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	451,000	0
Restructuring cost	18,000	2,528,000
Charges paid/settled	(433,000)	(2,077,000)
Ending balance	0	451,000	0
Ithaca Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	83,000	0
Restructuring cost	40,000	5,450,000
Charges paid/settled	(43,000)	(5,367,000)
Ending balance	0	83,000	0
Long Beach, Belfast and Sydney Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	89,000	0
Restructuring cost	0	6,265,000	6,300,000
Charges paid/settled	(89,000)	(6,176,000)
Ending balance	0	89,000	0
Employee related costs
Restructuring Reserve [Roll Forward]
Beginning balance	1,549,000	89,000	627,000
Restructuring cost	378,000	8,084,000	2,789,000
Charges paid/settled	(1,692,000)	(6,624,000)	(3,327,000)
Ending balance	235,000	1,549,000	89,000
Employee related costs | 2019 Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	1,536,000	0
Restructuring cost	378,000	6,265,000
Charges paid/settled	(1,679,000)	(4,729,000)
Ending balance	235,000	1,536,000	0
Employee related costs | Design Facility Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	0	0
Restructuring cost	0	338,000
Charges paid/settled	0	(338,000)
Ending balance	0	0	0
Employee related costs | Ithaca Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	13,000	0
Restructuring cost	0	1,481,000
Charges paid/settled	(13,000)	(1,468,000)
Ending balance	0	13,000	0
Employee related costs | Long Beach, Belfast and Sydney Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	89,000	0
Restructuring cost	0	2,789,000	2,800,000
Charges paid/settled	(89,000)	(2,700,000)
Ending balance	0	89,000	0
Facility related expenses
Restructuring Reserve [Roll Forward]
Beginning balance	978,000	0	0
Restructuring cost	761,000	11,459,000	3,476,000
Charges paid/settled	(1,713,000)	(10,481,000)	(3,476,000)
Ending balance	26,000	978,000	0
Facility related expenses | 2019 Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	457,000	0
Restructuring cost	819,000	5,300,000
Charges paid/settled	(1,250,000)	(4,843,000)
Ending balance	26,000	457,000	0
Facility related expenses | Design Facility Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	451,000	0
Restructuring cost	18,000	2,190,000
Charges paid/settled	(433,000)	(1,739,000)
Ending balance	0	451,000	0
Facility related expenses | Ithaca Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	70,000	0
Restructuring cost	40,000	3,969,000
Charges paid/settled	(30,000)	(3,899,000)
Ending balance	0	70,000	0
Facility related expenses | Long Beach, Belfast and Sydney Restructuring Plan
Restructuring Reserve [Roll Forward]
Beginning balance	0	0
Restructuring cost	0	3,476,000	3,500,000
Charges paid/settled	0	(3,476,000)
Ending balance	$ 0	$ 0	$ 0