Revenue, Deferred Revenue, Contract Balances and Performance Obligations - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Revenue from Contract with Customer [Abstract]
Deferred revenue	$ 13.5		$ 13.5		$ 10.7
Contract with customer, asset, net	4.8		4.8		$ 0.4
Contract with customer liability, revenue recognized	6.6	$ 11.3	8.8	$ 16.0
Contract with customer, liability, cumulative catch-up adjustment to revenue, change in estimate of transaction price	$ 0.4	$ 0.5	$ 2.1	$ 1.9