v3.25.3
PENSION PLANS AND RETIREMENT BENEFITS (Tables)
 9 Months Ended
Sep. 30, 2025
Retirement Benefits [Abstract]  
Components of Net Periodic Benefit (Income) Cost
Pension BenefitsOther Postretirement Benefits
 Three Months Ended September 30,Three Months Ended September 30,
2025202420252024
Components of Net Periodic Benefit (Income) Cost($ in millions)
Service cost$1.3 $1.4 $0.1 $— 
Interest cost24.9 25.5 0.4 0.2 
Expected return on plans’ assets(31.7)(33.5)— — 
Amortization of prior service cost(0.2)(0.2)0.3 (0.2)
Recognized actuarial loss (gain)1.4 1.6 — (0.1)
Net periodic benefit (income) cost$(4.3)$(5.2)$0.8 $(0.1)
Pension BenefitsOther Postretirement Benefits
 Nine Months Ended September 30,Nine Months Ended September 30,
2025202420252024
Components of Net Periodic Benefit (Income) Cost($ in millions)
Service cost$3.5 $3.9 $0.4 $0.4 
Interest cost74.3 76.1 1.1 1.1 
Expected return on plans’ assets(95.1)(101.2)— — 
Amortization of prior service cost(0.5)(0.5)0.1 (0.2)
Recognized actuarial loss4.4 4.9 0.2 0.4 
Net periodic benefit (income) cost$(13.4)$(16.8)$1.8 $1.7