REGULATORY MATTERS:	3 Months Ended
Mar. 31, 2026
Public Utilities, Rate Matters [Abstract]
Regulatory Matters	REGULATORY MATTERS Included below is a summary of Idaho Power's most recent general rate cases and base rate changes, as well as other recent or pending notable regulatory matters and proceedings. Idaho and Oregon Rate Cases Idaho Power's current base rates result from the IPUC and OPUC orders described in Note 3 - "Regulatory Matters" to the consolidated financial statements included in the 2025 Annual Report. Idaho ADITC Mechanism The 2018 Settlement Stipulation, 2023 Settlement Stipulation, and 2025 Settlement Stipulation are each described in Note 3 - "Regulatory Matters" to the consolidated financial statements included in the 2025 Annual Report. The 2025 Settlement Stipulation and the 2023 Settlement Stipulation modified the 2018 Settlement Stipulation in part. The 2023 Settlement Stipulation included provisions for the accelerated amortization of ADITCs to help achieve a minimum 9.12 percent Idaho ROE, while the 2025 Settlement Stipulation established an annual cap of $55 million on the amount of accelerated amortization of ADITCs for calendar year 2026 and thereafter and also modified the ADITC mechanism to include an additional amount of investment tax credits equal to the total of existing ADITCs not previously eligible for accelerated amortization under the mechanism and all investment tax credits generated through the end of calendar-year 2028. Based on its estimate of full-year 2026 Idaho ROE, for the three months ended March 31, 2026, Idaho Power recorded $6.3 million in additional ADITC amortization under the 2025 Settlement Stipulation. Accordingly, as of March 31, 2026, approximately $159.6 million of additional ADITCs remained available for future use. Idaho Power recorded $19.3 million of additional ADITC amortization for the three months ended March 31, 2025, based on its then-current estimate of full-year 2025 Idaho ROE. Power Cost Adjustment Mechanisms In both its Idaho and Oregon jurisdictions, Idaho Power's power cost adjustment mechanisms address the volatility of power supply costs and provide for annual adjustments to the rates charged to its retail customers. The power cost adjustment mechanisms compare Idaho Power's actual net power supply costs (primarily fuel and purchased power less wholesale energy sales) against net power supply costs being recovered in Idaho Power's retail rates. Under the power cost adjustment mechanisms, certain differences between actual net power supply costs incurred by Idaho Power and costs being recovered in retail rates are recorded as a deferred charge or accrued as a credit on the balance sheets for future recovery or refund. The power supply costs deferred or accrued primarily result from changes in the levels of Idaho Power's own power generation, changes in contracted power purchase prices and volumes, changes in wholesale market prices and transaction volumes, and changes in fuel prices. In April 2026, Idaho Power filed an application with the IPUC requesting a $51.6 million increase in PCA revenues as compared with the prior collection period, effective for the 2026-2027 PCA collection period from June 1, 2026 to May 31, 2027. The increase in PCA revenues is due primarily to a decrease in forecast hydroelectric generation for the April 2026 to March 2027 forecast period. As of the date of this report, the IPUC has not yet issued an order on the company's requested rate increase. In February 2026, Idaho Power filed its annual power cost adjustment mechanism filing with the OPUC. The filing also requested recovery of 2025 incremental deferred wildfire mitigation costs. If approved as filed, the filing would result in an increase of $1.9 million in Oregon-jurisdictional rates, effective June 1, 2026. As of the date of this report, the OPUC has not issued an order on the company's requested rate increase. In March 2026, Idaho Power filed the March forecast of its APCU with the OPUC. If the March forecast and October update are approved as filed, the 2026 composite APCU will result in an increase of $1.5 million in Oregon-jurisdictional revenues effective June 1, 2026. As of the date of this report, the OPUC has not issued an order on the company's requested rate increase. Idaho Fixed Cost Adjustment Mechanism The FCA mechanism, applicable to Idaho residential and small commercial customers, is designed to remove a portion of Idaho Power’s financial disincentive to invest in energy efficiency programs by separating (or decoupling) the recovery of fixed costs from the variable kilowatt-hour charge and linking it instead to a set amount per customer. Under Idaho Power's current rate design, recovery of a portion of fixed costs is included in the variable kilowatt-hour charge, which may result in over-collection or under-collection of fixed costs. To return over-collection to customers or to collect under-collection from customers, the FCA mechanism allows Idaho Power to accrue, or defer, the difference between the authorized fixed-cost recovery amount per customer and the actual fixed costs per customer recovered by Idaho Power during the year. The IPUC has discretion to cap the annual increase in the FCA recovery at 3 percent of base revenue, with any excess deferred for collection in a subsequent year. In March 2026, Idaho Power filed its annual FCA update with the IPUC, requesting approval to recover its 2025 FCA balance of $2.0 million, a $5.1 million increase over the 2024 FCA regulatory liability balance of $3.1 million, over the period from June 1, 2026, to May 31, 2027. As of the date of this report, the IPUC has not yet issued an order on the company's requested rate increase. Hells Canyon Complex Relicensing Costs In December 2025, Idaho Power filed an application with the IPUC requesting a determination that Idaho Power's HCC relicensing expenditures from January 1, 2016 through year-end 2025 were prudently incurred, and thus eligible for inclusion in retail rates in a future regulatory proceeding. As of the date of this report, the case remains pending. Wildfire Mitigation Cost Recovery The 2025 Settlement Stipulation authorized Idaho Power to defer certain incremental O&M and insurance costs for wildfire mitigation efforts above the 2024 base through the earlier of the next general rate case or 2027. As of March 31, 2026, Idaho Power’s deferral balance of Idaho-jurisdiction costs related to the WMP was $89.6 million, of which $70.9 million is approved to be amortized and currently collected in Idaho rates. In December 2025, Idaho Power filed its 2026-2028 WMP with the OPUC along with an application requesting authorization to defer for future recovery an estimated $3.1 million of newly identified incremental costs expected to be incurred in 2026 associated with expanded wildfire mitigation efforts. As of the date of this report, the case remains pending. As of March 31, 2026, Idaho Power’s deferral balance of Oregon-jurisdiction costs related to the WMP was $3.4 million, of which $0.6 million is approved to be amortized and currently collected in Oregon rates.

The 2018 Settlement Stipulation, 2023 Settlement Stipulation, and 2025 Settlement Stipulation are each described in Note 3 - "Regulatory Matters" to the consolidated financial statements included in the 2025 Annual Report. The 2025 Settlement Stipulation and the 2023 Settlement Stipulation modified the 2018 Settlement Stipulation in part. The 2023 Settlement Stipulation included provisions for the accelerated amortization of ADITCs to help achieve a minimum 9.12 percent Idaho ROE, while the 2025 Settlement Stipulation established an annual cap of $55 million on the amount of accelerated amortization of ADITCs for calendar year 2026 and thereafter and also modified the ADITC mechanism to include an additional amount of investment tax credits equal to the total of existing ADITCs not previously eligible for accelerated amortization under the mechanism and all investment tax credits generated through the end of calendar-year 2028.

Based on its estimate of full-year 2026 Idaho ROE, for the three months ended March 31, 2026, Idaho Power recorded $6.3 million in additional ADITC amortization under the 2025 Settlement Stipulation. Accordingly, as of March 31, 2026, approximately $159.6 million of additional ADITCs remained available for future use. Idaho Power recorded $19.3 million of additional ADITC amortization for the three months ended March 31, 2025, based on its then-current estimate of full-year 2025 Idaho ROE.

In both its Idaho and Oregon jurisdictions, Idaho Power's power cost adjustment mechanisms address the volatility of power supply costs and provide for annual adjustments to the rates charged to its retail customers. The power cost adjustment mechanisms compare Idaho Power's actual net power supply costs (primarily fuel and purchased power less wholesale energy sales) against net power supply costs being recovered in Idaho Power's retail rates. Under the power cost adjustment mechanisms, certain differences between actual net power supply costs incurred by Idaho Power and costs being recovered in retail rates are recorded as a deferred charge or accrued as a credit on the balance sheets for future recovery or refund. The power supply costs deferred or accrued primarily result from changes in the levels of Idaho Power's own power generation, changes in contracted power purchase prices and volumes, changes in wholesale market prices and transaction volumes, and changes in fuel prices.

In April 2026, Idaho Power filed an application with the IPUC requesting a $51.6 million increase in PCA revenues as compared with the prior collection period, effective for the 2026-2027 PCA collection period from June 1, 2026 to May 31, 2027. The increase in PCA revenues is due primarily to a decrease in forecast hydroelectric generation for the April 2026 to March 2027 forecast period. As of the date of this report, the IPUC has not yet issued an order on the company's requested rate increase.

In February 2026, Idaho Power filed its annual power cost adjustment mechanism filing with the OPUC. The filing also requested recovery of 2025 incremental deferred wildfire mitigation costs. If approved as filed, the filing would result in an increase of $1.9 million in Oregon-jurisdictional rates, effective June 1, 2026. As of the date of this report, the OPUC has not issued an order on the company's requested rate increase.

In March 2026, Idaho Power filed the March forecast of its APCU with the OPUC. If the March forecast and October update are approved as filed, the 2026 composite APCU will result in an increase of $1.5 million in Oregon-jurisdictional revenues effective June 1, 2026. As of the date of this report, the OPUC has not issued an order on the company's requested rate increase.

The FCA mechanism, applicable to Idaho residential and small commercial customers, is designed to remove a portion of Idaho Power’s financial disincentive to invest in energy efficiency programs by separating (or decoupling) the recovery of fixed costs from the variable kilowatt-hour charge and linking it instead to a set amount per customer. Under Idaho Power's current rate design, recovery of a portion of fixed costs is included in the variable kilowatt-hour charge, which may result in over-collection or under-collection of fixed costs. To return over-collection to customers or to collect under-collection from customers, the FCA mechanism allows Idaho Power to accrue, or defer, the difference between the authorized fixed-cost recovery amount per customer and the actual fixed costs per customer recovered by Idaho Power during the year. The IPUC has discretion to cap the annual increase in the FCA recovery at 3 percent of base revenue, with any excess deferred for collection in a subsequent year.

In March 2026, Idaho Power filed its annual FCA update with the IPUC, requesting approval to recover its 2025 FCA balance of $2.0 million, a $5.1 million increase over the 2024 FCA regulatory liability balance of $3.1 million, over the period from June 1, 2026, to May 31, 2027. As of the date of this report, the IPUC has not yet issued an order on the company's requested rate increase.

In December 2025, Idaho Power filed an application with the IPUC requesting a determination that Idaho Power's HCC relicensing expenditures from January 1, 2016 through year-end 2025 were prudently incurred, and thus eligible for inclusion in retail rates in a future regulatory proceeding. As of the date of this report, the case remains pending.

The 2025 Settlement Stipulation authorized Idaho Power to defer certain incremental O&M and insurance costs for wildfire mitigation efforts above the 2024 base through the earlier of the next general rate case or 2027. As of March 31, 2026, Idaho Power’s deferral balance of Idaho-jurisdiction costs related to the WMP was $89.6 million, of which $70.9 million is approved to be amortized and currently collected in Idaho rates.

In December 2025, Idaho Power filed its 2026-2028 WMP with the OPUC along with an application requesting authorization to defer for future recovery an estimated $3.1 million of newly identified incremental costs expected to be incurred in 2026 associated with expanded wildfire mitigation efforts. As of the date of this report, the case remains pending. As of March 31, 2026, Idaho Power’s deferral balance of Oregon-jurisdiction costs related to the WMP was $3.4 million, of which $0.6 million is approved to be amortized and currently collected in Oregon rates.