XML 48 R39.htm IDEA: XBRL DOCUMENT
v3.25.3

Regulatory Matters: Gas Utilities Regulatory Activity (Details) $ in Millions |  |  |  |  |  | 3 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Oct. 07, 2025 USD ($) | Jul. 24, 2025 USD ($) | May 06, 2025 USD ($) | May 05, 2025 USD ($) | Mar. 17, 2025 USD ($) | Dec. 31, 2024 USD ($) | Sep. 30, 2025 USD ($) | May 01, 2025 mi | Feb. 03, 2025 mi | Jun. 14, 2024 mi | May 01, 2024 mi
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Regulatory liability |  |  |  |  |  | $ 568.7 | $ 576.6 |  |  |  |
Colorado Public Utilities Commission (CPUC) | Black Hills Energy - Colorado Electric |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Weighted average cost of capital |  |  |  |  | 6.90% |  |  |  |  |  |
Public Utilities, Approved Rate Increase (Decrease), Amount |  |  | $ 17.5 | $ 17.0 | $ 17.0 |  |  |  |  |  |
Colorado Public Utilities Commission (CPUC) | Black Hills Energy - Colorado Electric | Minimum |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Public Utilities, Approved Equity Capital Structure, Percentage |  |  |  |  | 47.00% |  |  |  |  |  |
Public Utilities, Approved Debt Capital Structure, Percentage |  |  |  |  | 51.00% |  |  |  |  |  |
Public Utilities, Approved Return on Equity, Percentage |  |  |  |  | 9.30% |  |  |  |  |  |
Colorado Public Utilities Commission (CPUC) | Black Hills Energy - Colorado Electric | Maximum |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Public Utilities, Approved Equity Capital Structure, Percentage |  |  |  |  | 49.00% |  |  |  |  |  |
Public Utilities, Approved Debt Capital Structure, Percentage |  |  |  |  | 53.00% |  |  |  |  |  |
Public Utilities, Approved Return on Equity, Percentage |  |  |  |  | 9.50% |  |  |  |  |  |
Colorado Public Utilities Commission (CPUC) | Black Hills Energy - Colorado Electric | Rate Review Filed with the Regulatory Agency |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Public Utilities - Length of Electric Distribution Lines to Receive Infrastructure Investments | mi |  |  |  |  |  |  |  |  |  | 3,200 |
Public Utilities - Length of Electric Transmission Lines to Receive Infrastructure Investments | mi |  |  |  |  |  |  |  |  |  | 600 |
Iowa Utilities Commission (IUC) | Black Hills Energy - Iowa Gas |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Weighted average cost of capital |  |  |  |  |  | 7.20% |  |  |  |  |
Public Utilities, Approved Rate Increase (Decrease), Amount |  |  |  |  |  | $ 15.0 |  |  |  |  |
Iowa Utilities Commission (IUC) | Black Hills Energy - Iowa Gas | Rate Review Filed with the Regulatory Agency |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Public Utilities - Length of Natural Gas Pipeline to Receive Infrastructure Investments | mi |  |  |  |  |  |  |  |  |  |  | 5,000
Kansas Corporation Commission (KCC) | Black Hills Energy, Kansas Gas |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Public Utilities, Approved Rate Increase (Decrease), Amount |  | $ 10.8 |  |  |  |  |  |  |  |  |
Kansas Corporation Commission (KCC) | Black Hills Energy, Kansas Gas | GSRS Rider Revenue |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Public Utilities Amount of System Safety and Integrity Rider Moved to Base Rates |  | $ 4.4 |  |  |  |  |  |  |  |  |
Kansas Corporation Commission (KCC) | Black Hills Energy, Kansas Gas | Rate Review Filed with the Regulatory Agency |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Public Utilities - Length of Natural Gas Pipeline to Receive Infrastructure Investments | mi |  |  |  |  |  |  |  |  | 4,765 |  |
Nebraska Publc Service Commission (NPSC) | Black Hills Energy - Nebraska Gas | Rate Review Filed with the Regulatory Agency |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Public Utilities - Length of Natural Gas Pipeline to Receive Infrastructure Investments | mi |  |  |  |  |  |  |  | 12,900 |  |  |
Subsequent Event | Nebraska Publc Service Commission (NPSC) | Black Hills Energy - Nebraska Gas | Settlement reached with all intervenors for a general rate increase, subject to NPSC approval [Member] |  |  |  |  |  |  |  |  |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |  |  |  |  |  |  |  |  |
Public utilities, requested equity capital structure, percentage | 51.00% |  |  |  |  |  |  |  |  |  |
Public utilities, requested debt capital structure, percentage | 49.00% |  |  |  |  |  |  |  |  |  |
Public Utilities, Approved Return on Equity, Percentage | 9.85% |  |  |  |  |  |  |  |  |  |
Public Utilities, Approved Rate Increase (Decrease), Amount | $ 23.9 |  |  |  |  |  |  |  |  |  |

X
- Definition Public Utilities Amount of System Safety and Integrity Rider Moved to Base Rates + References No definition available. + Details
Name: | bkh_PublicUtilitiesAmountOfSystemSafetyAndIntegrityRiderMovedToBaseRates
Namespace Prefix: | bkh_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Public Utilities - Length of Electric Distribution Lines to Receive Infrastructure Investments + References No definition available. + Details
Name: | bkh_PublicUtilitiesLengthOfElectricDistributionLinesToReceiveInfrastructureInvestments
Namespace Prefix: | bkh_
Data Type: | dtr-types:lengthItemType
Balance Type: | na
Period Type: | instant

X
- Definition Public Utilities - Length of Electric Transmission Lines to Receive Infrastructure Investments + References No definition available. + Details
Name: | bkh_PublicUtilitiesLengthOfElectricTransmissionLinesToReceiveInfrastructureInvestments
Namespace Prefix: | bkh_
Data Type: | dtr-types:lengthItemType
Balance Type: | na
Period Type: | instant

X
- Definition Public Utilities - Length of Natural Gas Pipeline to Receive Infrastructure Investments + References No definition available. + Details
Name: | bkh_PublicUtilitiesLengthOfNaturalGasPipelineToReceiveInfrastructureInvestments
Namespace Prefix: | bkh_
Data Type: | dtr-types:lengthItemType
Balance Type: | na
Period Type: | instant

X
- Definition Weighted Average Cost of Capital + References No definition available. + Details
Name: | bkh_WeightedAverageCostOfCapital
Namespace Prefix: | bkh_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of public utility's approved debt to capital, including debt and equity. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesApprovedDebtCapitalStructurePercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of public utility's approved equity to capital, including debt and equity. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesApprovedEquityCapitalStructurePercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
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 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 Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesGeneralDisclosuresLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of public utility's requested debt to capital, including debt and equity. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesRequestedDebtCapitalStructurePercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of public utility's requested equity to capital, including debt and equity. + References No definition available. + Details
Name: | us-gaap_PublicUtilitiesRequestedEquityCapitalStructurePercentage
Namespace Prefix: | us-gaap_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount for the individual regulatory liability as itemized in a table of regulatory liabilities as of the end of the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Topic 980 -SubTopic 405 -Name Accounting Standards Codification -Section 25 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org/1943274/2147477571/980-405-25-1 + Details
Name: | us-gaap_RegulatoryLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_RegulatoryAgencyAxis=bkh_ColoradoPublicUtilitiesCommissionCPUCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=bkh_BlackHillsEnergyColoradoElectricMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PublicUtilitiesRegulatoryProceedingAxis=bkh_RateReviewFiledwiththeRegulatoryAgencyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAgencyAxis=bkh_IowaUtilitiesCommissionIUCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=bkh_BlackHillsEnergyIowaGasMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAgencyAxis=bkh_KansasCorporationCommissionKCCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=bkh_BlackHillsEnergyKansasGasMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_ProductOrServiceAxis=bkh_GSRSRiderRevenueMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RegulatoryAgencyAxis=bkh_NebraskaPublcServiceCommissionNPSCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=bkh_BlackHillsEnergyNebraskaGasMember
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: | us-gaap_PublicUtilitiesRegulatoryProceedingAxis=bkh_SettlementReachedWithAllIntervenorsForAGeneralRateIncreaseSubjectToNpscApprovalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |