Employee Benefit Plans - Amounts Recognized in Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain (loss)	$ (32.0)	$ (35.0)
Prior service cost	(0.2)	(0.3)
Total amount recognized	(32.2)	(35.3)
Postretirement Medical and Other
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gain (loss)	8.3	7.0
Prior service cost	0.0	0.0
Total amount recognized	$ 8.3	$ 7.0