v3.25.2
Retirement Benefits (Tables)
 6 Months Ended
Jun. 30, 2025
Retirement Benefits [Abstract]  
Schedule of Net Pension and Retiree Health (Benefit) Cost
Net pension and retiree health (benefit) cost included the following components:
Defined Benefit Pension Plans
Three Months Ended June 30,Six Months Ended June 30,
 2025202420252024
Components of net periodic cost:
Service cost$82.5 $85.6 $166.2 $169.4 
Interest cost175.0 165.7 347.8 330.7 
Expected return on plan assets(271.6)(277.9)(541.1)(555.5)
Amortization of prior service cost0.5 0.5 1.0 1.0 
Recognized actuarial loss21.9 31.8 42.8 62.4 
Net periodic cost$8.3 $5.7 $16.7 $8.0 
Retiree Health Benefit Plans
Three Months Ended June 30,Six Months Ended June 30,
 2025202420252024
Components of net periodic benefit:
Service cost$8.1 $9.5 $16.4 $17.7 
Interest cost16.2 15.6 32.0 31.1 
Expected return on plan assets(46.2)(48.0)(92.4)(96.1)
Amortization of prior service benefit(0.1)(1.4)(0.2)(2.8)
Recognized actuarial gain(1.1)(0.7)(1.9)(1.3)
Net periodic benefit$(23.1)$(25.0)$(46.1)$(51.4)