Retirement Plans - Components of Net Periodic Benefit Cost (Credit) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Defined Benefit Plan Disclosure [Line Items]
Interest cost	$ 0.1	$ 0.1	$ 0.2	$ 0.2
Prior service cost	(0.2)	(0.2)	(0.4)	(0.4)
Total benefit cost	(0.1)	(0.1)	(0.2)	(0.2)
Defined Benefit Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	3.8	4.0	7.4	8.1
Interest cost	5.0	4.8	9.7	9.6
Expected return on assets	(5.2)	(4.6)	(10.0)	(9.3)
Net loss (gain)	0.1	(0.4)	0.2	(0.8)
Prior service cost	0.2	0.1	0.3	0.3
Curtailments	(0.0)	(1.3)	(0.0)	(1.3)
Total benefit cost	$ 3.9	$ 2.6	$ 7.6	$ 6.6