v3.26.1
EMPLOYEE BENEFIT PLANS (Notes)
 3 Months Ended
Mar. 31, 2026
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]  
Employee Benefit Plans (Notes) EMPLOYEE BENEFIT PLANS
The following tables set forth the components of net periodic benefit cost (credit) for our pension, inclusive of our defined benefit pension plan, supplemental executive retirement plan, and other postemployment benefit plans for the periods indicated:

Pension Benefits
Three Months Ended
March 31,
20262025
(Thousands of dollars)
Components of net periodic benefit cost (credit)
 
Service cost$1,291 $1,337 
Interest cost (a)
9,525 10,042 
Expected return on assets (a)
(10,490)(11,910)
Amortization of unrecognized prior service cost (credit) (a)
93 93 
Amortization of net loss (gain) (a)
4,220 1,865 
Net periodic benefit cost (credit)
$4,639 $1,427 
(a) These amounts, net of any amounts capitalized as a regulatory asset, have been recognized as other (income) expense, net in the consolidated statement of income. See Note 11 for additional detail.
Other Postemployment Benefits
Three Months Ended
March 31,
20262025
(Thousands of dollars)
Components of net periodic benefit cost (credit)
Service cost$110 $123 
Interest cost (a)
2,020 2,069 
Expected return on assets (a)
(2,194)(2,212)
Amortization of unrecognized prior service cost (credit) (a)
— — 
Amortization of net loss (gain) (a)
(8)(31)
Net periodic benefit cost (credit)
$(72)$(51)
(a) These amounts, net of any amounts capitalized as a regulatory asset, have been recognized as other (income) expense, net in the consolidated statement of income. See Note 11 for additional detail.
We recover qualified pension benefit plan and other postemployment benefit plan costs through rates charged to our customers. Certain regulatory authorities require that the recovery of these costs be based on specific guidelines. The difference between these regulatory-based amounts and the periodic benefit cost calculated pursuant to GAAP is deferred as a regulatory asset or liability and amortized to expense over periods in which this difference will be recovered in rates, as authorized by the applicable regulatory authorities. For the three months ended March 31, 2026 and 2025, regulatory deferrals related to net periodic benefit cost (credit) were $(1.1) million and $(0.3) million, respectively.

We capitalize all eligible service cost and non-service (credit) components under the accounting requirements of ASC Topic 980 (Regulated Operations) for rate-regulated entities. Capitalized non-service (credits) reflected in pension and other postemployment benefit costs, net within regulatory assets in our consolidated balance sheets were $(6.0) million and $(6.8) million at March 31, 2026 and December 31, 2025, respectively. See Note 3 of the Notes to Consolidated Financial Statements in this Quarterly Report for additional information.

Nonqualified Deferred Compensation Plan - We have a nonqualified deferred compensation plan with obligations of $21.9 million both at March 31, 2026 and December 31, 2025, which are reported within other deferred credits in our consolidated balance sheets. These obligations represent the amount owed to plan participants and are treated as if invested in specified deemed investment options. A significant portion of the obligation is indirectly funded with key-person corporate-owned life insurance policies to offset costs associated with our nonqualified deferred compensation plan and the supplemental executive retirement plan. These corporate-owned life insurance policies are measured at cash surrender value of $45.4 million and $46.2 million at March 31, 2026, and December 31, 2025, respectively, and are reported within other assets in our consolidated balance sheets.

Gains (losses) on the corporate-owned life insurance policies are recognized in other income (expense), net within our consolidated statements of income; see Note 11 for additional detail of our other income (expense), net. Deferred compensation expense (income) associated with the nonqualified deferred compensation plan is recognized in operations and maintenance expense within our consolidated statements of income were $(0.5) million and $(0.3) million for the three months ended March 31, 2026 and 2025, respectively.