v3.25.2
Benefit Plans and Other Postretirement Benefits (Tables)
 6 Months Ended
Jun. 30, 2025
Retirement Benefits [Abstract]  
Components of Net Periodic Benefit Cost (Credit)
 Three Months Ended June 30
 2025202420252024
(Millions of Dollars)Pension BenefitsPostretirement Health
Care Benefits
Service cost$5 $5 $— $— 
Interest cost (a)
15 14 5 4 
Expected return on plan assets (a)
(20)(19)(5)(4)
Amortization of net loss (a)
2 1 1 — 
Net periodic benefit cost 2 1 1 — 
Effects of regulation(1)(4)— — 
Net benefit cost (credit) recognized for financial reporting$1 $(3)$1 $— 
Six Months Ended June 30
2025202420252024
(Millions of Dollars)Pension BenefitsPostretirement Health
Care Benefits
Service cost$10 $10 $— $— 
Interest cost (a)
30 28 10 8 
Expected return on plan assets (a)
(40)(38)(9)(8)
Amortization of net loss (a)
3 3 1 1 
Net periodic benefit cost 3 3 2 1 
Effects of regulation(2)(4)— — 
Net benefit cost (credit) recognized for financial reporting$1 $(1)$2 $1 
(a)The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the consolidated statements of income or capitalized on the consolidated balance sheets as a regulatory asset.