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Regulatory Matters: Electric Utilities Regulatory Activity (Details) $ in Thousands |  | 12 Months Ended | 24 Months Ended
--- | --- | --- | ---
Oct. 15, 2020 MW | Dec. 31, 2021 USD ($) | Dec. 31, 2021 USD ($)
Black Hills Energy - South Dakota Electric | Federal Energy Regulatory Commission (FERC) Common Use System (CUS) |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Annual Revenue Requirement, as Required by the FERC Joint-Access Transmission Tariff |  | $ 26,000 |
Capital Addition Requirements by the FERC Joint-Access Transmission Tariff |  |  | $ 5,000
Black Hills Wyoming and Wyoming Electric | Federal Energy Regulatory Commission (FERC) |  |  |
Public Utilities, General Disclosures [Line Items] |  |  |
Number of Megawatts Capacity Purchased | MW | 60 |  |
Long-term Purchase Commitment, Period | 11 years |  |

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