v3.26.1
Pension Plan and Other Postretirement Benefits (Tables)
6 Months Ended
Jun. 30, 2026
Retirement Benefits [Abstract]  
Schedule of Components of Net Periodic Benefit Costs for the Pension Plans and Other Postretirement Benefits
The following tables list components of net periodic benefit costs for the pension plans and other postretirement benefits. The data listed under “pension plan” includes the qualified pension plan and the non-qualified SERP. The data listed under “other benefits” is for all other postretirement benefit plans.
Pension PlanOther Benefits
 Three Months Ended June 30,
 2026202520262025
Service cost$5,782 $5,207 $1,331 $1,408 
Interest cost10,231 9,553 1,641 1,773 
Expected return on plan assets(14,275)(12,793)(3,680)(3,197)
Amortization of prior service cost131 131 39 39 
Recognized net actuarial loss (gain)
606 194 (962)(522)
Net periodic benefit cost (credit)$2,475 $2,292 $(1,631)$(499)
Pension PlanOther Benefits
 Six Months Ended June 30,
 2026202520262025
Service cost$11,564 $10,414 $2,661 $2,816 
Interest cost20,463 19,106 3,283 3,546 
Expected return on plan assets(28,551)(25,586)(7,359)(6,394)
Amortization of prior service cost262 262 78 78 
Recognized net actuarial loss (gain)
1,212 388 (1,925)(1,044)
Net periodic benefit cost (credit)$4,950 $4,584 $(3,262)$(998)