Employee Benefit Plans - Share Based Compensation by Cost and Expense Categories (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	$ 44.0	$ 55.7	$ 86.0	$ 89.6
Stock options
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	1.8	3.2	3.7	3.3
RSUs, RSAs, and PSAs
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	37.3	47.7	72.2	76.8
ESPP
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	4.9	4.8	10.1	9.5
Cost of revenues - Product
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	1.1	1.6	2.5	3.5
Cost of revenues - Service
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	3.4	4.4	7.6	8.9
Research and development
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	19.0	26.2	34.2	38.4
Sales and marketing
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	13.2	15.1	27.0	24.5
General and administrative
Stock Based Compensation Expense Recorded in Cost and Expense Categories
Share-based compensation expense	$ 7.3	$ 8.4	$ 14.7	$ 14.3