Share-Based Compensation - Effects of Stock-Based Compensation Expense Related to Stock-Based Awards to Employees and Non-Employees - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jul. 03, 2020	Jun. 28, 2019	Jul. 03, 2020	Jun. 28, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	$ 8,495	$ 2,815	$ 26,921	$ 20,163
Cost of Revenue
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	814	651	2,771	2,165
Research and Development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	2,921	2,517	9,939	6,540
Selling, General and Administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	$ 4,760	$ (353)	$ 14,211	$ 11,458