Other Financial Information - Deferred Revenue (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred Revenue [Line Items]
Deferred revenue	$ 1,285.8	$ 1,223.4
Reported as:
Current deferred revenue	867.3	812.9
Long-term deferred revenue	418.5	410.5
Product
Deferred Revenue [Line Items]
Deferred revenue	104.7	132.6
Service
Deferred Revenue [Line Items]
Deferred revenue	$ 1,181.1	$ 1,090.8