v3.24.1.u1
Pensions and Postretirement Benefits Other than Pensions (Components of the Company's Pension-Related Costs) (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2024
Mar. 31, 2023
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) $ (2.7) $ (5.6)
Pension Costs [Member]    
Service cost 8.1 8.6
Interest cost 28.2 29.8
Expected return on plan assets (29.4) (29.9)
Net amortization of prior service costs 0.7 0.9
Net amortization of plan net actuarial losses 3.8 4.0
Net periodic pension benefit cost 11.4 13.4
Net curtailment loss 0.0 (1.1)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) 11.4 14.5
Pension Costs [Member] | Discontinued Operations [Member]    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) 1.7 1.7
Operating Income (Loss) [Member] | Pension Costs [Member] | Continuing Operations [Member]    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) 7.0 7.5
Other Nonoperating Income (Expense) [Member] | Pension Costs [Member] | Continuing Operations [Member]    
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) $ 2.7 $ 5.3