Unusual Items - Summary of Unusual Items Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Unusual or Infrequent Item [Line Items]
Loss on debt	$ 22.7	$ 0.9	$ 22.7	$ 10.5
Unusual Items
Unusual or Infrequent Item [Line Items]
Legal matters (component of other expense, net)	(0.4)	0.0	15.7	0.0
Proxy contest and related litigation costs (component of other expense, net)	16.3	0.0	28.3	0.0
Terminated merger costs (component of other expense, net)	0.0	7.2	2.5	20.8
Loss on debt	22.7	0.9	22.7	10.5
Total unusual items	$ 38.6	$ 8.1	$ 69.2	$ 31.3