Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net periodic benefit cost	$ 9.5	$ 2.8
Pension Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	3.6	0.7
Interest cost	11.6	3.3
Expected return on plan assets	(9.3)	(3.9)
Amortization of prior service benefit (cost)	0.1	0.1
Amortization of net loss	1.8	1.4
Net periodic benefit cost	7.8	1.6
Other Postretirement Benefits
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0.1	0.0
Interest cost	1.3	1.0
Amortization of net loss	0.3	0.2
Net periodic benefit cost	$ 1.7	$ 1.2