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ASSET RETIREMENT OBLIGATIONS | 12 Months Ended
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Dec. 31, 2025
Asset Retirement Obligation [Abstract] |
Asset Retirement Obligation Disclosure | ASSET RETIREMENT OBLIGATIONS (ARO) The guidance relating to accounting for AROs requires that legal obligations associated with the retirement of property, plant, and equipment be recognized as a liability at fair value when incurred and when a reasonable estimate of the fair value of the liability can be made. Under the guidance, when a liability is initially recorded, the entity increases the carrying amount of the related long-lived asset to reflect the future retirement cost. Over time, the liability is accreted to its estimated settlement value and paid, and the capitalized cost is depreciated over the useful life of the related asset. If, at the end of the asset’s life, the recorded liability differs from the actual obligations paid, a gain or loss would be recognized. As a rate-regulated entity, Idaho Power defers accretion, depreciation, and gains or losses as regulatory assets, as approved by the IPUC, until such ARO costs are included in customer rates for collection. The regulatory assets recorded under this order do not earn a return on investment. Idaho Power’s recorded AROs relate to the reclamation and removal costs at its jointly-owned thermal generation facilities. In 2025, changes in estimates at the jointly-owned thermal generation facilities resulted in a net increase of $21.6 million in the recorded AROs. The increase is primarily related to updated post-closure cost estimates for a flue gas desulfurization pond at the Jim Bridger plant which was retired in December 2025. Idaho Power also has additional AROs associated with its transmission system and generation facilities; however, due to the indeterminate removal date, the fair value of the associated liabilities currently cannot be estimated and no amounts are recognized in the consolidated financial statements. Idaho Power also collects removal costs in rates for certain assets that do not have associated AROs. Idaho Power is required to classify these removal costs as regulatory liabilities, see Note 3 - "Regulatory Matters" for the removal costs recorded as regulatory liabilities on IDACORP’s and Idaho Power’s consolidated balance sheets as of December 31, 2025 and 2024. The following table presents the changes in the carrying amount of AROs (in thousands of dollars):
|  | 2025 |  | 2024
Balance at January 1 |  | $ | 51,126 |  |  | $ | 48,997 |
Accretion expense |  | 2,457 |  |  | 1,895 |
Revisions in estimated cash flows |  | 21,642 |  |  | 842 |
Liability settled |  | (1,249) |  |  | (608) |
Balance at December 31 |  | $ | 73,976 |  |  | $ | 51,126 |

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- Definition The entire disclosure for an asset retirement obligation and the associated long-lived asset. An asset retirement obligation is a legal obligation associated with the disposal or retirement from service of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Subparagraph (a) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481850/410-20-50-1 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 410 -SubTopic 20 -Name Accounting Standards Codification -Publisher FASB -URI https://asc.fasb.org/410-20/tableOfContent Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Name Accounting Standards Codification -Section 50 -Paragraph 2 -SubTopic 20 -Topic 410 -Publisher FASB -URI https://asc.fasb.org/1943274/2147481850/410-20-50-2 + Details
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