Other Financial Information - Other Expense, Net (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Other Financial Information [Abstract]
Interest income	$ 15.0	$ 23.5
Interest expense	(20.1)	(24.2)
(Loss) gain on investments, net	(5.8)	1.6
Other	(0.2)	0.9
Other (expense) income, net	$ (11.1)	$ 1.8