Share-Based Compensation - Effects of Stock-Based Compensation Expense Related to Stock-Based Awards to Employees and Non-Employees (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 03, 2020	Mar. 29, 2019	Apr. 03, 2020	Mar. 29, 2019
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	$ 10,276	$ 8,076	$ 18,426	$ 17,349
Cost of Revenue
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	995	841	1,957	1,514
Research and Development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	4,111	1,200	7,018	4,022
Selling, General and Administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total share-based compensation expense	$ 5,170	$ 6,035	$ 9,451	$ 11,813