Income Tax - Unrecognized Tax Benefits Balance (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Estimated interest and penalties	$ 0.1	$ 11.4	$ 2.9
Unrecognized tax positions	28.0	235.7	72.4	$ 51.6
Total unrecognized tax benefits	28.1	247.1	75.3
Presented net against non-current deferred tax assets	26.7	142.1	68.4
Current (included in accounts payable and other current liabilities)	0.0	98.0	0.0
Non-current (included within other liabilities)	1.4	7.0	6.9
Total unrecognized tax benefits	28.1	247.1	75.3
Amount of unrecognized tax benefits that would impact the effective tax rate, if recognized	$ 18.6	$ 87.7	$ 72.4