Unusual Items - Summary of Unusual Items Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Unusual or Infrequent Item [Line Items]
Loss on debt	$ 0.0	$ 9.1
Unusual Items
Unusual or Infrequent Item [Line Items]
Legal matters (component of other expense, net)	16.1	0.0
Proxy contest and related litigation costs (component of other expense, net)	3.1	0.0
Terminated merger costs (component of other expense, net)	2.5	7.5
Loss on debt	0.0	9.1
Total unusual items	$ 21.7	$ 16.6