Stock-Based Compensation - Stock-Based Compensation Expense in Consolidated Statements of Operations (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 30, 2024	Apr. 01, 2023	Mar. 30, 2024	Apr. 01, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 25.8	$ 23.2	$ 54.5	$ 43.7
Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3.2	2.7	5.9	5.6
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3.0	3.1	6.2	6.5
Selling and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	3.6	3.0	6.9	6.3
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 16.0	$ 14.4	$ 35.5	$ 25.3