Stock-Based Compensation - Stock Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Jan. 02, 2021	Dec. 28, 2019
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	$ 10,613	$ 6,936
Capitalized share-based compensation costs	1,900	1,000
Amortization of capitalized share-based compensation expenses	2,300	1,200
Total compensation cost, unvested stock-based awards granted but not yet recognized	$ 63,800
Total compensation cost, weighted-average period of amortization (in years)	1 year 9 months 18 days
Period End
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Capitalized share-based compensation remaining	$ 2,400	1,200
Cost of sales
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	2,272	1,182
Research and development
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	1,199	561
Selling, general and administrative
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	8,714	6,049
Income tax benefit
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Income tax benefit	$ (1,572)	$ (856)