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Regulatory Matters: Electric Utilities Regulatory Activity (Details) $ in Thousands			12 Months Ended
	Jan. 01, 2022	Jan. 01, 2020 USD ($)	Dec. 31, 2020 USD ($)	Oct. 15, 2020 MW
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			$ 27,000
Capital Addition Requirements by the FERC Joint-Access Transmission Tariff		$ 33,000
Black Hills Energy, South Dakota Electric | South Dakota Public Utilities Commission (SDPUC)
Public Utilities, General Disclosures [Line Items]
Public Utilities, Moratorium Period			6 years
Public Utilities, Increase in Moratorium Period			3 years
Public Utilities, Previous Approved Moratorium Period			6 years
Black Hills Energy, South Dakota Electric | South Dakota Public Utilities Commission (SDPUC) | Application for Deferred Accounting Treatment Withdrawn
Public Utilities, General Disclosures [Line Items]
Public Utilities, Development Costs Expensed			$ 5,400
Black Hills Wyoming and Wyoming Electric | Federal Energy Regulatory Commission (FERC)
Public Utilities, General Disclosures [Line Items]
Number of Megawatts Capacity Purchased | MW				60
Black Hills Wyoming and Wyoming Electric | Federal Energy Regulatory Commission (FERC) | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Public Utilities Term of Power Purchase Agreement	11 years

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