Geographic and Significant Customer Information - Summary of Customer Concentrations as Percentage of Total Sales and Accounts Receivable (Detail) - Customer Concentration Risk	12 Months Ended
	Oct. 02, 2020	Sep. 27, 2019	Sep. 28, 2018
Total Sales
Segment Reporting Information [Line Items]
Concentration risk, percentage	61.00%	54.00%	57.00%
Total Sales | Customer A
Segment Reporting Information [Line Items]
Concentration risk, percentage	14.00%	16.00%	13.00%
Total Sales | Customer B
Segment Reporting Information [Line Items]
Concentration risk, percentage	12.00%	0.00%	0.00%
Total Sales | Customer C
Segment Reporting Information [Line Items]
Concentration risk, percentage	12.00%	0.00%	0.00%
Accounts Receivable | Customer A
Segment Reporting Information [Line Items]
Concentration risk, percentage	20.00%	24.00%
Accounts Receivable | Customer D
Segment Reporting Information [Line Items]
Concentration risk, percentage	8.00%	10.00%