Employee Stock Benefit Plans (Components of Stock-based Compensation Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Jan. 01, 2021	Jan. 03, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 122.6	$ 83.0	$ 75.0
Cost of sales
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	9.5	6.7	5.6
Research and development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	29.5	22.1	16.7
Sales and marketing
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	21.5	16.2	13.0
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	62.1	38.0	39.7
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	110.5	73.2	67.3
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	1.3	1.5	0.6
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation expense	$ 10.8	$ 8.3	$ 7.1