Long-term Debt - Interest Expense, Net (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Debt Disclosure [Abstract]
Interest expense	$ (134.2)	$ (114.8)	$ (401.8)	$ (346.4)
Interest income	0.6	0.2	1.2	0.7
Capitalized interest	0.1	0.0	0.1	0.0
Interest expense, net	$ (133.5)	$ (114.6)	$ (400.5)	$ (345.7)