Long-term Debt - Interest Expense, Net (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Debt Disclosure [Abstract]
Interest expense	$ (139.1)	$ (135.7)	$ (275.7)	$ (266.1)
Interest income	0.2	0.2	0.4	0.4
Capitalized interest	0.9	0.5
Capitalized interest			1.6	0.9
Interest expense, net	(138.0)	(135.0)	(273.7)	(264.8)
Coupon interest	2.2	1.2	4.5	1.2
Amortization of debt discount	3.1	1.4	6.2	1.4
Amortization of debt issuance costs	0.3	0.1	0.5	0.1
Convertible Notes interest expense	$ 5.6	$ 2.7	$ 11.2	$ 2.7