XML 101 R74.htm IDEA: XBRL DOCUMENT
v3.25.4

REGULATORY MATTERS: Idaho Base Rate Changes (Details) - USD ($) $ in Thousands |  | 12 Months Ended |  |
--- | --- | --- | --- | ---
Oct. 15, 2024 | Dec. 31, 2026 | Sep. 30, 2026 | Dec. 31, 2025 | Oct. 15, 2025 | Dec. 31, 2024 | Dec. 31, 2023 | Jan. 01, 2026 | Jan. 01, 2024
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Regulatory Assets |  |  |  |  | $ 1,564,458 |  | $ 1,507,372 |  |  |
Wildfire Mitigation Plan Deferral |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Regulatory Assets | [1] |  |  |  | 91,670 |  | 63,966 |  |  |
2023 Rate Case | Benefit Obligations [Member] |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Public Utilities, Requested Rate Increase (Decrease), Amount |  |  |  |  |  |  | 18,000 |  |  |
Settlement Stipulation - Investment Tax Credits and Idaho Sharing Mechanism |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Effective Income Tax Rate Reconciliation, Tax Credit, Investment, Amount |  |  |  |  | 40,300 |  |  |  |  |
Settlement Stipulation - Investment Tax Credits and Idaho Sharing Mechanism | ADITC |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Effective Income Tax Rate Reconciliation, Tax Credit, Investment, Amount |  |  |  |  | 167,800 |  |  |  |  |
2025 Rate Case | Idaho Power Cost Adjustment [Member] | Subsequent Event |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Approved Rate Increase (Decrease), Amount |  |  | $ 13,100 |  |  |  |  |  |  |
IDAHO | 2024 Limited Rate Case |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Approved Rate Increase (Decrease), Amount |  |  |  |  | 50,600 |  |  |  |  |
IDAHO | 2023 Rate Case | Idaho Power Company |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Public Utilities, Requested Rate Increase (Decrease), Amount |  |  |  |  |  |  | 3,500 |  |  |
IDAHO | Wildfire Mitigation Plan Deferral |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Regulatory Assets |  |  |  |  | $ 88,200 |  |  |  |  |
IDAHO | Hells Canyon Complex | Subsequent Event |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Approved Rate Increase (Decrease), Amount |  |  |  | $ 29,700 |  |  |  |  |  |
IDAHO | May 2018 Tax Reform Settlement Stipulation |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Amortization of Regulatory Asset |  |  |  |  |  |  |  | $ 7,400 |  |
IDAHO | May 2018 Tax Reform Settlement Stipulation | Annual recurring |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Approved Rate Increase (Decrease), Amount |  |  |  |  |  |  |  | $ 18,700 |  |
IDAHO | 2023 Rate Case |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount |  |  |  |  |  |  | $ 54,700 |  |  |
Authorized Return on Equity in Rate Case, Minimum |  |  |  |  |  |  |  |  |  | 9.12%
Authorized Return on Equity in Rate Case, Mid-point |  |  |  |  |  |  |  |  |  | 9.60%
Approved Return on Equity, Percentage |  |  |  |  |  |  | 9.60% |  |  |
Approved Authorized Rate of Return |  |  |  |  |  |  | 7.247% |  |  |
IDAHO | 2023 Rate Case | Idaho Power Cost Adjustment [Member] |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount |  |  |  |  |  |  | $ 168,300 |  |  |
IDAHO | Idaho PCA includes power supply and deferral balance. |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount |  |  |  |  |  |  | $ 484,900 |  |  |
IDAHO | Idaho PCA includes power supply and deferral balance. | Subsequent Event |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Approved Rate Increase (Decrease), Amount |  |  | $ 468,800 |  |  |  |  |  |  |
IDAHO | 2024 Limited Rate Case |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Approved Rate Increase (Decrease), Percentage |  |  |  |  | 3.70% |  |  |  |  |
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount |  |  |  |  | $ 50,100 |  |  |  |  |
IDAHO | 2025 Rate Case |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Percentage to be Shared with Customers |  |  |  |  | 80.00% |  |  |  |  |
Percentage to be Shared with Entity |  |  |  |  | 20.00% |  |  |  |  |
IDAHO | 2025 Rate Case | Subsequent Event |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Approved Rate Increase (Decrease), Percentage |  |  | 7.48% |  |  |  |  |  |  |
Authorized Return on Equity in Rate Case, Minimum |  |  |  |  |  |  |  |  | 9.12% |
Approved Rate Increase (Decrease), Amount |  |  | $ 110,000 |  |  |  |  |  |  |
Approved Return on Equity, Percentage |  |  | 9.60% |  |  |  |  |  |  |
Approved Authorized Rate of Return |  |  | 7.41% |  |  |  |  |  |  |
IDAHO | 2025 Rate Case | Idaho Power Cost Adjustment [Member] | Subsequent Event |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Approved Rate Increase (Decrease), Amount |  |  | $ (16,100) |  |  |  |  |  |  |
IDAHO | 2025 Rate Case | Wildfire Mitigation Plan Deferral |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Regulatory Assets |  |  |  |  | $ 73,900 |  |  |  |  |
OREGON | Subsequent Event |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Approved Rate Increase (Decrease), Percentage |  |  | 0.90% |  |  |  |  |  |  |
Approved Rate Increase (Decrease), Amount |  |  | $ (600) |  |  |  |  |  |  |
OREGON | Wildfire mitigation plan costs | Subsequent Event |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Approved Rate Increase (Decrease), Amount |  |  | 700 |  |  |  |  |  |  |
OREGON | Wildfire Mitigation Plan Deferral |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Regulatory Assets |  |  |  |  | $ 3,500 |  |  |  |  |
OREGON | Valmy Plant | Subsequent Event |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Approved Rate Increase (Decrease), Amount |  |  | $ (1,200) |  |  |  |  |  |  |
OREGON | 2023 Rate Case |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Approved Rate Increase (Decrease), Percentage |  |  |  |  |  | 12.14% |  |  |  |
Approved Rate Increase (Decrease), Amount |  |  |  |  |  | $ 6,700 |  |  |  |
Approved Return on Equity, Percentage |  | 9.50% |  |  |  |  |  |  |  |
OREGON | 2023 Rate Case | Cost of Capital and Capital Structure |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Authorized Rate of Return in Rate Case |  | 7.302% |  |  |  |  |  |  |  |
Total Retail Rate Base |  | $ 188,900 |  |  |  |  |  |  |  |
OREGON | 2023 Rate Case | Cost of Debt Capital Structure [Domain] |  |  |  |  |  |  |  |  |  |
Idaho Base Rate Changes [Line Items] |  |  |  |  |  |  |  |  |  |
Approved Rate of Return |  | 5.104% |  |  |  |  |  |  |  |
[1] | This item is discussed in more detail in this Note 3 - "Regulatory Matters."

X
- Definition [Line Items] for 2011 Idaho General Rate Case Settlement [Table] + References No definition available. + Details
Name: | ida_A2011IdahoGeneralRateCaseSettlementLineItems
Namespace Prefix: | ida_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Approved Authorized Rate of Return + References No definition available. + Details
Name: | ida_ApprovedAuthorizedRateOfReturn
Namespace Prefix: | ida_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Approved Rate of Return + References No definition available. + Details
Name: | ida_ApprovedRateOfReturn
Namespace Prefix: | ida_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The authorized rate of return, whether requested or approved, in the rate case. + References No definition available. + Details
Name: | ida_AuthorizedRateOfReturnInRateCase
Namespace Prefix: | ida_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Authorized Return on Equity in Rate Case, Mid-point + References No definition available. + Details
Name: | ida_AuthorizedReturnOnEquityInRateCaseMidPoint
Namespace Prefix: | ida_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The minimum authorized return on equity, whether requested or approved, in the rate case. + References No definition available. + Details
Name: | ida_AuthorizedReturnOnEquityInRateCaseMinimum
Namespace Prefix: | ida_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of earnings to be Shared with Customers that is above the applicable authorized rate of return in the rate case. + References No definition available. + Details
Name: | ida_PercentageToBeSharedWithCustomers
Namespace Prefix: | ida_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of earnings to be Shared with the Entity that is above the applicable authorized rate of return in the rate case. + References No definition available. + Details
Name: | ida_PercentageToBeSharedWithEntity
Namespace Prefix: | ida_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Total retail rate base contemplated in the rate case. + References No definition available. + Details
Name: | ida_TotalRetailRateBase
Namespace Prefix: | ida_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The expense charged against earnings during the period to allocate the capitalized costs of regulatory assets over the periods expected to benefit from such costs. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Name Accounting Standards Codification -Section 45 -Paragraph 28 -Subparagraph (b) -SubTopic 10 -Topic 230 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482740/230-10-45-28 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 220 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(3)) -Publisher FASB -URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2 + Details
Name: | us-gaap_AmortizationOfRegulatoryAsset
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to investment tax credit. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 12A -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org/1943274/2147482685/740-10-50-12A Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 740 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 12 -Publisher FASB -URI https://asc.fasb.org/1943274/2147482685/740-10-50-12 + Details
Name: | us-gaap_IncomeTaxReconciliationTaxCreditsInvestment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of public utility's approved rate increase (decrease) by regulatory agency. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesApprovedRateIncreaseDecreaseAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Percentage of public utility's approved rate increase (decrease) by regulatory agency. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesApprovedRateIncreaseDecreasePercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of public utility's approved return on equity. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesApprovedReturnOnEquityPercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of public utility's amended requested rate increase (decrease) with regulatory agency. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesRequestedRateIncreaseDecreaseAmendedAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of public utility's requested rate increase (decrease) with regulatory agency. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesRequestedRateIncreaseDecreaseAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The amount for the individual regulatory asset as itemized in a table of regulatory assets as of the end of the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 980 -SubTopic 340 -Name Accounting Standards Codification -Section 50 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147478742/980-340-50-1 + Details
Name: | us-gaap_RegulatoryAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_RegulatoryAssetAxis=ida_WildfireMitigationPlanDeferralMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RateCasesAxis=ida_A2023RateCaseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RateCaseMatterAxis=ida_BenefitObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RateCasesAxis=ida_SettlementStipulationInvestmentTaxCreditsAndIdahoSharingMechanismMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_AvailabilityFutureUseAxis=ida_ADITCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RateCasesAxis=ida_A2025RateCaseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RateCaseMatterAxis=ida_IdahoPowerCostAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RegulatoryJurisdictionAxis=stpr_ID
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RateCaseMatterAxis=ida_A2024LimitedRateCaseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RateCaseMatterAxis=ida_A2023RateCaseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_EnergyEfficiencyRiderAxis=ida_IdahoPowerCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RateCaseMatterAxis=ida_WildfireMitigationPlanDeferralMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RateCaseMatterAxis=ida_HellsCanyonComplexMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RateCasesAxis=ida_May2018TaxReformSettlementStipulationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RateCaseMatterAxis=ida_AnnualrecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RateCasesAxis=ida_IdahoPCAIncludesPowerSupplyAndDeferralBalanceMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RateCasesAxis=ida_A2024LimitedRateCaseMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RegulatoryJurisdictionAxis=stpr_OR
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RateCaseMatterAxis=ida_WildfireMitigationPlanCostsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_RateCaseMatterAxis=ida_ValmyPlantMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_ReturnAxis=ida_CostOfCapitalAndCapitalStructureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ida_ReturnAxis=ida_CostOfDebtCapitalStructureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |