Employee Benefit Plans - Share Based Compensation by Cost and Expense Categories (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	$ 52.7	$ 57.5	$ 138.7	$ 147.1
Stock options
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	1.5	2.3	5.2	5.6
RSUs, RSAs, and PSAs
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	45.8	50.9	118.0	127.7
ESPP
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	5.4	4.3	15.5	13.8
Cost of revenues - Product
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	1.4	0.8	3.9	4.3
Cost of revenues - Service
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	4.0	4.1	11.6	13.0
Research and development
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	22.9	29.6	57.1	68.0
Sales and marketing
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	16.4	15.5	43.4	40.0
General and administrative
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	$ 8.0	$ 7.5	$ 22.7	$ 21.8