Revenue - Contract Balances (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Accounts receivable, net	$ 246.2	$ 269.3
Short-term contract assets	0.5	1.0
Long-term contract assets	1.0	2.8
Short-term deferred revenue	520.8	467.5
Long-term deferred revenue	$ 11.8	$ 7.8