Other Financial Information - Deferred Revenue (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Reported as:
Current	$ 854.7	$ 812.9
Long-term	400.1	410.5
Deferred revenue	1,254.8	1,223.4
Undelivered product commitments and other product deferrals
Deferred product revenue:
Deferred gross product revenue	121.0	141.7
Product
Deferred product revenue:
Deferred gross product revenue	121.0	141.7
Deferred cost of product revenue	(9.5)	(9.1)
Reported as:
Deferred revenue	111.5	132.6
Service
Reported as:
Deferred revenue	$ 1,143.3	$ 1,090.8