Unusual Items - Summary of Unusual Items Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Unusual or Infrequent Item [Line Items]
Merger costs	$ 20.0	$ 0.0
Unusual Items
Unusual or Infrequent Item [Line Items]
Merger costs	20.0	0.0
Legal matters	0.0	16.1
Proxy contest and related litigation costs	0.0	3.1
Terminated merger costs	0.0	2.5
Total unusual items	$ 20.0	$ 21.7