Contract Assets and Deferred Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Revenue from Contract with Customer [Abstract]
Contract assets - current	$ 45.1		$ 44.3
Contract assets - long-term	18.8		20.7
Deferred revenue - current	(248.0)		(257.1)
Deferred revenue - long-term	(138.3)		$ (137.9)
Revenue recognized that was included in deferred revenue at the beginning of the period	$ 99.1	$ 81.0