Segments - Revenues by Customer Vertical (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Total net revenues	$ 1,188.8	$ 1,138.2	$ 3,435.5	$ 3,222.5
Cloud
Segment Reporting Information [Line Items]
Total net revenues	303.3	253.1	894.6	800.5
Service Provider
Segment Reporting Information [Line Items]
Total net revenues	445.8	475.1	1,327.7	1,286.8
Enterprise
Segment Reporting Information [Line Items]
Total net revenues	$ 439.7	$ 410.0	$ 1,213.2	$ 1,135.2