v3.26.3
BENEFIT PLANS:
 9 Months Ended
Sep. 30, 2026
Retirement Benefits, Description [Abstract]  
Benefit Plans BENEFIT PLANS
Idaho Power has the noncontributory defined benefit pension plan and two nonqualified defined benefit plans for certain senior management employees called the SMSP. Idaho Power also has a nonqualified defined benefit pension plan for directors that was frozen in 2002. Remaining vested benefits from that plan are included with the SMSP in the disclosures below. The benefits under the pension plan are based on years of service and the employee’s final average earnings. Idaho Power also maintains a defined benefit postretirement benefit plan (consisting of health care and death benefits) that covers all employees who were enrolled in the active-employee group plan at the time of retirement as well as their spouses and qualifying dependents. The table below shows the components of net periodic benefit costs for the pension, SMSP, and postretirement benefits plans for the three months ended September 30, 2026 and 2025 (in thousands of dollars).
Pension PlanSMSPPostretirement
Benefits		Total
20262025202620252026202520262025
Service cost$8,168 $8,115 $240 $293 $166 $168 $8,574 $8,576 
Interest cost14,539 14,379 1,430 1,410 735 743 16,704 16,532 
Expected return on plan assets(18,539)(17,229)— — (453)(447)(18,992)(17,676)
Amortization of prior service cost2 2 55 55 275 344 332 401 
Amortization of net loss— — 241 173 (422)(441)(181)(268)
Net periodic benefit cost4,170 5,267 1,966 1,931 301 367 6,437 7,565 
Regulatory deferral of net periodic benefit cost(1)
(3,985)(5,058)— — — — (3,985)(5,058)
Previously deferred pension costs recognized(1)
8,796 8,796 — — — — 8,796 8,796 
Net periodic benefit cost recognized for financial reporting(1)(2)
$8,981 $9,005 $1,966 $1,931 $301 $367 $11,248 $11,303 
(1)  Net periodic benefit costs for the pension plan are recognized for financial reporting based upon the authorization of each regulatory jurisdiction in which Idaho Power operates. Under IPUC order, the Idaho portion of net periodic benefit cost is recorded as a regulatory asset and is recognized in the income statement as those costs are recovered through rates.
(2)  Of total net periodic benefit cost recognized for financial reporting, $9.8 million and $9.8 million, respectively, were recognized in "Other operations and maintenance" and $1.6 million and $1.5 million, respectively, were recognized in "Other income, net" on the condensed consolidated statements of income of the companies for the three months ended September 30, 2026 and 2025.
The table below shows the components of net periodic benefit costs for the pension, SMSP, and postretirement benefits plans for the nine months ended September 30, 2026 and 2025 (in thousands of dollars).
Pension PlanSMSPPostretirement
Benefits		Total
20262025202620252026202520262025
Service cost$24,505 $23,830 $720 $879 $497 $504 $25,722 $25,213 
Interest cost43,617 42,113 4,291 4,230 2,207 2,230 50,115 48,573 
Expected return on plan assets(55,617)(51,698)— — (1,360)(1,340)(56,977)(53,038)
Amortization of prior service cost5 5 166 166 824 1,031 995 1,202 
Amortization of net loss— — 721 518 (1,266)(1,324)(545)(806)
Net periodic benefit cost12,510 14,250 5,898 5,793 902 1,101 19,310 21,144 
Regulatory deferral of net periodic benefit cost(1)
(11,955)(13,620)— — — — (11,955)(13,620)
Previously deferred pension costs recognized(1)
26,387 26,387 — — — — 26,387 26,387 
Net periodic benefit cost recognized for financial reporting(1)(2)
$26,942 $27,017 $5,898 $5,793 $902 $1,101 $33,742 $33,911 
(1)  Net periodic benefit costs for the pension plan are recognized for financial reporting based upon the authorization of each regulatory jurisdiction in which Idaho Power operates. Under IPUC order, the Idaho portion of net periodic benefit cost is recorded as a regulatory asset and is recognized in the income statement as those costs are recovered through rates.
(2)  Of total net periodic benefit cost recognized for financial reporting, $29.1 million and $29.4 million, respectively, were recognized in "Other operations and maintenance" and $4.6 million and $4.5 million, respectively, were recognized in "Other income, net" on the condensed consolidated statements of income of the companies for the nine months ended September 30, 2026 and 2025.
Idaho Power has no minimum contribution to its pension plan required in 2026. During the nine months ended September 30, 2026, Idaho Power contributed $20 million in a continued effort to balance the regulatory collection of these expenditures with the amount and timing of contributions, as well as to mitigate the cost of being in an underfunded position. The primary impact of pension contributions is on the timing of cash flows, as the timing of cost recovery lags behind contributions.

Idaho Power also has an Employee Savings Plan that complies with Section 401(k) of the Internal Revenue Code and covers substantially all employees. Idaho Power matches specified percentages of employee contributions to the Employee Savings Plan.