Employee Benefit Plans - Additional Information (Detail) - USD ($)	12 Months Ended
	Sep. 27, 2019	Sep. 28, 2018	Sep. 29, 2017
Domestic Plan \| Calender Year 2017
Employee Benefit Plan [Line Items]
Discretionary matching contribution		$ 2,700,000
Domestic Plan \| Calender Year 2018
Employee Benefit Plan [Line Items]
Discretionary matching contribution	$ 2,600,000
Domestic Plan \| Calender Year 2019
Employee Benefit Plan [Line Items]
Discretionary matching contribution	0
Domestic Plan \| Calender Year 2016
Employee Benefit Plan [Line Items]
Discretionary matching contribution			$ 2,400,000
Foreign Plan
Employee Benefit Plan [Line Items]
Discretionary matching contribution	$ 1,100,000	$ 1,200,000	$ 1,300,000