75000 - Document - Cover Page
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75010 - Document - Audit Information
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75020 - Statement - Consolidated Statements of Income
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75030 - Statement - Consolidated Statements of Comprehensive Income
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75040 - Statement - Consolidated Statements of Comprehensive Income (Parentheticals)
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75050 - Statement - Consolidated Balance Sheets
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75060 - Statement - Consolidated Balance Sheets (Parenthetical)
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75070 - Statement - Consolidated Statements of Cash Flows
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75080 - Statement - Consolidated Statements of Equity
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75090 - Statement - Consolidated Statements of Equity (Parenthetical)
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995455 - Disclosure - Cybersecurity Risk Management, Strategy and Governance
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995465 - Disclosure - Business Description And Significant Accounting Policies
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995475 - Disclosure - Regulatory Matters
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995485 - Disclosure - Commitment, Contingencies And Guarantees
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995495 - Disclosure - Revenue
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995505 - Disclosure - Property, Plant And Equipment
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995515 - Disclosure - Jointly Owned Facilities
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995525 - Disclosure - Asset Retirement Obligations:
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995535 - Disclosure - Financing
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995545 - Disclosure - Risk Management And Derivatives
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995555 - Disclosure - Fair Value Measurements
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995565 - Disclosure - Other Comprehensive Income
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995575 - Disclosure - Variable Interest Entity
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995585 - Disclosure - Employee Benefits Plans
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995595 - Disclosure - Share-based Compensation Plans
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995605 - Disclosure - Income Taxes
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995615 - Disclosure - Business Segment Information
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995625 - Disclosure - Pending Merger with NorthWestern Energy
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995635 - Disclosure - Subsequent Events
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995645 - Disclosure - Business Description And Significant Accounting Policies (Policies)
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995655 - Disclosure - Business Description And Significant Accounting Policies (Tables)
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995665 - Disclosure - Regulatory Matters (Tables)
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995675 - Disclosure - Commitment, Contingencies And Guarantees (Tables)
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995685 - Disclosure - Revenue (Tables)
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995695 - Disclosure - Property, Plant and Equipment (Tables)
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995705 - Disclosure - Jointly Owned Facilities (Tables)
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995715 - Disclosure - Asset Retirement Obligations (Tables)
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995725 - Disclosure - Financing (Tables)
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995735 - Disclosure - Risk Management And Derivatives (Tables)
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995745 - Disclosure - Fair Value Measurements (Tables)
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995755 - Disclosure - Other Comprehensive Income (Tables)
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995765 - Disclosure - Variable Interest Entity (Tables)
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995775 - Disclosure - Employee Benefit Plans (Tables)
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995785 - Disclosure - Share-based Compensation Plans (Tables)
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995795 - Disclosure - Income Taxes (Tables)
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995805 - Disclosure - Business Segment Information (Tables)
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995815 - Disclosure - Business Description And Significant Accounting Policies: Accounts Receivable (Details)
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995825 - Disclosure - Business Description And Significant Accounting Policies: Changes to Allowance for Credit Losses (Details)
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995835 - Disclosure - Business Description And Significant Accounting Policies: Materials, Supplies and Fuel (Details)
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995845 - Disclosure - Business Description And Significant Accounting Policies: Property, Plant and Equipment (AFUDC) (Details)
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995855 - Disclosure - Business Description And Significant Accounting Policies: Goodwill (Details)
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995865 - Disclosure - Business Description And Significant Accounting Policies: Schedule of Intangible Assets (Details)
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995875 - Disclosure - Business Description And Significant Accounting Policies: Accrued Liabilities (Details)
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995885 - Disclosure - Business Description And Significant Accounting Policies: Earnings Per Share Reconciliation (Details)
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995895 - Disclosure - Business Description And Significant Accounting Policies: Contingencies and Environmental Liabilities (Details)
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995905 - Disclosure - Regulatory Matters: Regulatory Matters (Details)
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995915 - Disclosure - Regulatory Matters: Winter Storm Uri (Details)
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995925 - Disclosure - Regulatory Matters: Colorado Renewable Energy (Details)
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995935 - Disclosure - Regulatory Matters: Gas and Electric Utilities Recent Regulatory Activity (Details)
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995945 - Disclosure - Commitment, Contingencies And Guarantees: Power Purchase Agreement - Related Party (Details)
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995955 - Disclosure - Commitment, Contingencies And Guarantees: Unconditional Purchase Obligations (Details)
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995965 - Disclosure - Commitment, Contingencies And Guarantees: Lease Agreements (Details)
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995975 - Disclosure - Commitment, Contingencies And Guarantees: Reclamation Liability (Details)
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995985 - Disclosure - Commitment, Contingencies And Guarantees: Manufactured Gas Plants (Details)
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995995 - Disclosure - Commitments, Contingencies and Guarantees: GT Resources, LLC v Black Hills Corp (Details)
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996005 - Disclosure - Commitments, Contingencies and Guarantees: Gain Contingency (Details)
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996015 - Disclosure - Commitment, Contingencies And Guarantees: Guarantees (Details)
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996025 - Disclosure - Revenue: Disaggregation of Revenue (Details)
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996035 - Disclosure - Property, Plant and Equipment (Details)
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996045 - Disclosure - Jointly Owned Facilities (Details)
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996055 - Disclosure - Asset Retirement Obligations (Details)
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996065 - Disclosure - Financing - Schedule of Short-term Debt and Narrative (Details)
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996075 - Disclosure - Financing: Long-Term Debt (Details)
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996085 - Disclosure - Financing: Long-Term Debt: Aggregate Maturities of Long Term Debt and Associated Interest Payments (Details)
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996095 - Disclosure - Financing: Long-term Debt (Additional Information) (Details)
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996105 - Disclosure - Financing: Debt Covenants (Additional Information) (Details)
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996115 - Disclosure - Financing: Dividend Restrictions (Details)
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996125 - Disclosure - Financing: Equity (Details)
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996135 - Disclosure - Financing: At-the-Market Equity Offering Program (Details)
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996145 - Disclosure - Financing: Summary of ATM Activity (Details)
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996155 - Disclosure - Financing: Summary of ATM Activity (Parenthetical) (Details)
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996165 - Disclosure - Financing: Shareholder Dividend Reinvestment and Stock Purchase Plan (Details)
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996175 - Disclosure - Risk Management and Derivatives: Utilities (Details)
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996185 - Disclosure - Risk Management and Derivatives: Derivatives by Balance Sheet Classification (Details)
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996195 - Disclosure - Risk Management and Derivatives: Cash Flow Hedges (Details)
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996205 - Disclosure - Risk Management and Derivatives: Derivatives Not Designated as Hedge Instruments (Details)
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996215 - Disclosure - Fair Value Measurements: Schedule of Fair Values (Details)
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996225 - Disclosure - Fair Value Measurements: Schedule of Fair Value of Investments in Equity Securities (Details)
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996235 - Disclosure - Fair Value Measurements: Other Fair Value Measurements (Details)
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996245 - Disclosure - Other Comprehensive Income: Reclassification Out of Accumulated Other Comprehensive Income (Loss) (Details)
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996255 - Disclosure - Other Comprehensive Income: Accumulated Other Comprehensive Income (Details)
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996265 - Disclosure - Variable Interest Entity: (Details)
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996275 - Disclosure - Employee Benefit Plans: Defined Contribution Plans (Details)
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996285 - Disclosure - Employee Benefit Plans: Defined Benefit Pension Plan (Details)
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996295 - Disclosure - Employee Benefit Plans: Non-pension Defined Benefit Retiree Healthcare Plan (Details)
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996305 - Disclosure - Employee Benefit Plans: Plan Contributions (Details)
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996315 - Disclosure - Employee Benefit Plans: Fair Value Measurements (Details)
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996325 - Disclosure - Employee Benefit Plans: Components of Net Periodic Expense (Details)
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996335 - Disclosure - Employee Benefit Plans: Employee Benefit Plan Obligations (Details)
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996345 - Disclosure - Employee Benefit Plans: Assumptions (Details)
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996355 - Disclosure - Share-based Compensation Plans: Compensation Related Costs, Share Based Payments (Details)
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996365 - Disclosure - Share-based Compensation Plans: Restricted Stock (Details)
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996375 - Disclosure - Share-based Compensation Plans: Performance Plan Share Units (Details)
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996385 - Disclosure - Share-based Compensation Plans: Performance Share Units-Market Condition (Details)
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996395 - Disclosure - Share-based Compensation Plans: Performance Condition (Details)
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996405 - Disclosure - Income Taxes (Additional Information) (Details)
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996415 - Disclosure - Income Taxes: Current and Deferred Income Tax (Expense) Benefit (Details)
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996425 - Disclosure - Income Taxes: Effective Tax Rate Differences From Statutory Tax Rates (Details)
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996435 - Disclosure - Income Taxes - Effective Tax Rate Differences From Statutory Tax Rates (Parenthetical) (Details)
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996445 - Disclosure - Income Taxes: Income Taxes (Paid) Received (Details)
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996455 - Disclosure - Income Taxes: Deferred Income Tax Assets and Liabilities (Details)
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996465 - Disclosure - Income Taxes: Net Operating Loss and and Tax Credit Carryforwards (Details)
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996475 - Disclosure - Income Taxes: Reconciliation of unrecognized tax benefits (Details)
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996485 - Disclosure - Income Taxes: Interest, Penalties and Audits (Details)
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996495 - Disclosure - Business Segment Information (Details)
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996505 - Disclosure - Business Segment Information: Information Relating to Segments Statement of Income (Details)
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996515 - Disclosure - Business Segment Information: Capital Expenditures and Asset Acquisitions (Details)
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996525 - Disclosure - Pending Merger with NorthWestern Energy - Additional Information (Details)
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996535 - Disclosure - Subsequent Events (Details)
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Fixed Income
Fixed Income Funds [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value
Vested (usd per share)
Retirement Plan Type [Axis]
Retirement Plan Type [Axis]
Schedule of Accumulated and Projected Benefit Obligations
Schedule of Accumulated and Projected Benefit Obligations [Table Text Block]
Segments [Domain]
Segments [Domain]
Reporting Segment [Domain]
Common Collective Trust, Fixed Income Fund
Common Collective Trust, Fixed Income Fund [Member]
Common Collective Trued, Fixed Income Fund [Member]
Common Collective Trust - Fixed Income
Unrecorded Unconditional Purchase Obligation, to be Paid, Year Three
2028
Transmission Tie
Transmission Tie [Member]
Jointly onwed Transmission Tie [Member]
Over the Counter
Over-the-Counter [Member]
Defined Contribution Plan, Employee Vesting Period
Defined Contribution Plan, Employee Vesting Period
Period over which an employee vests in a defined contribution plan.
Fair Value Measurements
Derivatives and Fair Value [Text Block]
Entity Incorporation, State or Country Code
Entity Incorporation, State or Country Code
Balance Sheet Location [Domain]
Statement of Financial Position Location, Balance [Domain]
Transferred Renewable Credits Net of Discount [Member]
Transferred renewable credits net of discount.
Transferred Renewable Credits Net of Discount
Employer contributions
Defined Benefit Plan, Plan Assets, Contributions by Employer
Payment for Pension Benefits
Effective Income Tax Rate Reconciliation, Tax Credit, Amount [Abstract]
Tax credits
Interest expense incurred net of amounts capitalized [Member]
Interest expense incurred net of amounts capitalized.
Interest Expense Incurred Net Of Amounts Capitalized
Long-term debt, net of current maturities
Long-term debt, net of current maturities
Long-Term Debt, Excluding Current Maturities
Long-Term Debt, Excluding Current Maturities, Total
Schedule of Long-term Debt Instruments
Schedule of Long-Term Debt Instruments [Table Text Block]
Plan Name [Axis]
Plan Name [Axis]
Transportation [Member]
Transportation
Transportation [Member]
Public Utilities General Disclosures [Table]
Public Utilities General Disclosures [Table]
Entity Current Reporting Status
Entity Current Reporting Status
Black Hills Wyoming and Wyoming Electric
Black Hills Wyoming and Wyoming Electric [Member]
Black Hills Wyoming and Wyoming Electric [Member]
Unrecorded Unconditional Purchase Obligation [Table]
Unrecorded Unconditional Purchase Obligation [Table]
Operating expenses:
Operating Expenses [Abstract]
Fair Value, Inputs, Level 2
Fair Value, Inputs, Level 2 [Member]
Total deferred tax assets
Deferred Tax Assets, Net of Valuation Allowance
Cash Flow Hedging
Cash Flow Hedging [Member]
Common stock, shares authorized
Common Stock, Shares Authorized
Public utilities amount of requested system safety and integrity rider be moved to base rates.
Public Utilities Amount Of Requested System Safety And Integrity Rider Be Moved To Base Rates
Public Utilities, Amount of Requested System Safety and Integrity Rider be Moved to Base Rates
Total Unrealized Losses
Debt and Equity Securities, Unrealized Loss
Debt and Equity Securities, Unrealized Loss
Future Amortization Expense, Year Four
Finite-Lived Intangible Asset, Expected Amortization, Year Four
Other Nonoperating Income (Expense)
Other Nonoperating Income (Expense) [Member]
Asset Retirement Obligations
Asset Retirement Obligation [Policy Text Block]
Investments
Investment, Policy [Policy Text Block]
Effective Income Tax Reconciliation Amortization Of Excess Deferred Income Tax Expense Amount
Effective income tax reconciliation amortization of excess deferred income tax expense amount.
Amortization of excess deferred income taxes
Product and Service [Axis]
Product and Service [Axis]
Nebraska
NEBRASKA
Document Fiscal Period Focus
Document Fiscal Period Focus
Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years
2031- 2035
Expected long-term rate of return on assets
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-Term Rate of Return on Plan Assets
Total other assets, non-current
Assets, Noncurrent, Other than Noncurrent Investments and Property, Plant and Equipment
Current liabilities
Liability, Defined Benefit Plan, Current
Stated interest rate (percent)
Debt Instrument, Interest Rate, Stated Percentage
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Abstract]
Entity Shell Company
Entity Shell Company
Other (none of which is individually significant)
Other Accrued Liabilities, Current
Dividends on common stock
Dividends, Common Stock, Cash
Plant in Service
Jointly Owned Utility Plant, Gross Ownership Amount of Plant in Service
Segment Reporting
Segment Reporting, Policy [Policy Text Block]
Senior Unsecured Notes Due 2021
Senior Unsecured Notes Due 2021 [Member]
Senior Unsecured Notes Due 2021
Cash and cash equivalents
Cash and Cash Equivalent
Cash and Cash Equivalents, at Carrying Value, Total
Schedule of Maturities of Long-term Debt
Schedule of Maturities of Long-Term Debt [Table Text Block]
Distributions to non-controlling interest
Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders
Regulatory Agency [Domain]
Regulatory Agency [Domain]
Defined Benefit Plan, Benefit Obligation
Benefit obligation at beginning of year
Benefit obligation at end of year
Performance Share Units - Performance Condition
Performance Share Units - Performance Condition [Member]
Performance Share Units - Performance Condition
Defined Benefit Plan, Expected Future Benefit Payment, Year Two
2027
Cybersecurity Risk Management, Strategy, and Governance [Abstract]
Common stock, shares, issued
Common Stock, Shares, Issued
Cybersecurity Risk Management Positions or Committees Responsible Report to Board [Flag]
Schedule of Short-term Debt [Table]
Short-Term Debt [Table]
Asset Class [Domain]
Statement [Table]
Statement [Table]
Energy [Axis]
Energy [Axis]
Additions for current year tax positions
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions
Internal Revenue Service (IRS)
Internal Revenue Service (IRS) [Member]
Regulatory Liability [Axis]
Regulatory Liability [Axis]
Long-term Purchase Commitment, Category of Item Purchased [Domain]
Long-Term Purchase Commitment, Category of Item Purchased [Domain]
Liability Hedging Assets [Member]
Liability hedging assets.
Liability-hedging Assets
Guarantor Obligations, Nature [Domain]
Guarantor Obligations, Nature [Domain]
Schedule of Amounts Recognized in Balance Sheet
Schedule of Amounts Recognized in Balance Sheet [Table Text Block]
Beginning Balance
Ending Balance
Asset Retirement Obligation
Asset Retirement Obligation, Total
Statement [Line Items]
Statement [Line Items]
Business Combination [Domain]
Revenue from Contract with Customer [Policy Text Block]
Revenue Recognition
Entity Filer Category
Entity Filer Category
Variable Interest Entity
Variable Interest Entity Disclosure [Text Block]
Natural Gas
Natural Gas [Member]
Purchased Gas Cost Obligation [Member]
Purchased Gas Cost Obligation
Purchased Gas Cost Obligation [Member]
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]
Deferred Tax Liabilities, Regulatory Assets
Regulatory assets
TOTAL LIABILITIES AND TOTAL EQUITY
Liabilities and Equity
BusinessAcquisitionExchangeOfCommonStockParOrStatedValuePerShare
Business acquisition exchange of common stock par or stated value per share.
Business acquisition exchange of common stock par value per share
Derivative Asset, Fair Value, Amount Not Offset Against Collateral
Derivative Asset, Subject to Master Netting Arrangement, before Offset of Collateral
Derivative Asset, Subject to Master Netting Arrangement, before Offset of Collateral, Total
Debt Instrument [Line Items]
Debt Instrument [Line Items]
2023
Long-Term Debt, Current Maturities, Total
Less current maturities
Less current maturities
Current maturities of long-term debt
Long-Term Debt, Maturity, Year Three
2028
Property, Plant and Equipment, Type [Axis]
Long-Lived Tangible Asset [Axis]
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount
Operating Loss Carryforwards [Table]
Operating Loss Carryforwards [Table]
Fair Value, by Balance Sheet Grouping
Fair Value, by Balance Sheet Grouping [Table Text Block]
Public utilities, requested equity capital structure, percentage
Public Utilities, Requested Equity Capital Structure, Percentage
Hedging Relationship [Axis]
Hedging Relationship [Axis]
Black Hills Corporation Pension Plan
Black Hills Retirement Plan [Member]
Black Hills Retirement Plan [Member]
Derivative Instruments Losses Reclassified from Accumulated OCI Into Income Effective Portion
Derivative instruments losses reclassified from accumulated OCI into income effective portion.
Cybersecurity Risk Third Party Oversight and Identification Processes [Flag]
Deferred Tax Liability, State
Amount of deferred tax liabilities attributable to taxable temporary differences from state taxes.
State deferred tax liability
Proceeds from Issuance of Debt
Proceeds from Issuance of Debt
At The Market Equity Offering Program Shares Issued
At The Market Equity Offering Program Shares Issued
At The Market Equity Offering Program Shares Issued
Number of shares issued
Derivative [Line Items]
Derivative [Line Items]
Wholesale
Wholesale [Member]
Wholesale [Member]
Less: Valuation allowance
Deferred Tax Assets, Valuation Allowance
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent
U.S. federal corporate tax rate
U.S. Federal statutory rate, percent
Subsequent Event [Line Items]
Subsequent Event [Line Items]
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amount
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amount, Total
Nontaxable or Nondeductible Items
Cybersecurity Risk Management Third Party Engaged [Flag]
Documents Incorporated by Reference
Documents Incorporated by Reference [Text Block]
Goodwill
Goodwill
Goodwill, Total
Goodwill, Beginning Balance
Goodwill, Ending Balance
Other adjustments, net
Other Noncash Income (Expense)
Other Noncash Income (Expense), Total
Effective Income Tax Rate Reconciliation, Percent
Effective Tax Rate, percent
Recoveries and Other Additions
Accounts Receivable, Allowance for Credit Loss, Recovery
Interest income
Investment Income, Interest
Income Tax Authority [Axis]
Income Tax Jurisdiction [Axis]
Accretion
Asset Retirement Obligation, Accretion Expense
Summary of Income Tax Contingencies
Summary of Income Tax Contingencies [Table Text Block]
Common Collective Trust, Cash And Cash Equivalents
Common Collective Trust, Cash And Cash Equivalents [Member]
Common Collective Trust, Cash And Cash Equivalents [Member]
Geographical [Domain]
Energy-related tax credits, net of transferability discount
Effective Income Tax Rate Reconciliation, Tax Credit, Energy-Related, Amount
Cash and Cash Equivalents and Restricted Cash
Cash and Cash Equivalents, Restricted Cash and Cash Equivalents, Policy [Policy Text Block]
Settlement Agreement Filed With Regulatory Agency
Settlement Agreement Filed with Regulatory Agency [Member]
Settlement agreement filed with regulatory agency.
Accrued benefit cost at December 31
Defined Benefit Plan Accrued Benefit Cost
Defined benefit plan accrued benefit cost.
Schedule of Changes in Projected Benefit Obligations
Schedule of Changes in Projected Benefit Obligations [Table Text Block]
Schedule of Variable Interest Entities [Table]
Variable Interest Entity [Table]
Materials, Supplies and Fuel
Schedule of Inventory, Current [Table Text Block]
Less Accumulated Depreciation
Jointly Owned Utility Plant, Ownership Amount of Plant Accumulated Depreciation
Goodwill
Deferred Tax Liabilities, Goodwill
Postretirement Health Coverage
Postretirement Health Coverage [Member]
Healthcare Plan
Electricity
Electricity [Member]
Less unamortized deferred financing costs
Deferred Financing Costs
Less unamortized deferred financing costs
Debt Issuance Costs, Net
Debt Issuance Costs, Net, Total
Benefits paid
Defined Benefit Plan, Plan Assets, Benefits Paid
Lessor, Operating Lease, Payments, Fiscal Year Maturity [Abstract]
Lessor, Operating Lease, Payment to be Received, Fiscal Year Maturity [Abstract]
Senior Unsecured Notes Due 2049
Senior Unsecured Notes Due 2049 [Member]
Senior Unsecured Notes Due 2049 [Member]
At The Market Equity Program Proceeds from Sale of Stock
At The Market Equity Program Proceeds from Sale of Stock
At The Market Equity Program Proceeds from Sale of Stock
Proceeds, (net of issuance costs)
Percent of recent average market price
Common Stock Purchase Percentage of Recent Average Market Price
Common stock purchase percentage of recent average market price
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment [Line Items]
Regulatory assets, current
Regulatory assets, current
Regulatory Asset, Current
Finite-Lived Intangible Assets, Useful Life
Finite-Lived Intangible Asset, Useful Life
Unusual or Infrequent Item, or Both [Domain]
Unusual or Infrequent Item, or Both [Domain]
Guarantor Obligations by Nature [Axis]
Guarantor Obligations, Nature [Axis]
Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate Service Cost
Defined benefit plan assumptions used calculating net periodic benefit cost discount rate service cost.
Service cost effective discount rate
Disaggregation of Revenue [Table]
Public Utilities Amount of System Safety and Integrity Rider Moved to Base Rates
Public Utilities Amount of System Safety and Integrity Rider Moved to Base Rates
Public Utilities, Amount of System Safety and Integrity Rider Moved to Base Rates
Cybersecurity Risk Management, Strategy, and Governance [Table]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]
Schedule of Earnings Per Share Reconciliation
Weighted average common shares outstanding:
Weighted Average Number of Shares Outstanding, Basic and Diluted [Abstract]
Weighted average number of shares of common stock, basic and diluted[Abstract]
Other operating activities, net
Increase (Decrease) in Other Operating Assets and Liabilities, Net
Increase (Decrease) in Other Operating Assets and Liabilities, Net, Total
SEC Schedule, 12-09, Valuation Allowances and Reserves, Additions, Charge to Cost and Expense
Valuation allowance, increase to tax expense
Equity Securities [Member]
Investment in privately held oil and gas company
Equity securities
Gas, Storage
Natural Gas, Storage [Member]
Nontaxable or Nondeductible Items
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Amount [Abstract]
Earnings per share, Basic (usd per share)
Earnings Per Share, Basic
Earnings Per Share, Basic, Total
Disaggregation of Revenue
Disaggregation of Revenue [Table Text Block]
Repayment of long term debt
Long-term debt - repayments
Repayments of Long-Term Debt
Repayments of Long-Term Debt, Total
Employee Benefit Plans
Retirement Benefits [Text Block]
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate
Pension benefit obligation effective discount rate
Debt Discounts, Premiums and Deferred Financing Costs
Debt, Policy [Policy Text Block]
Variable Interest Entity [Line Items]
Variable Interest Entity [Line Items]
Revolving Credit Facility
Revolving Credit Facility [Member]
Derivative, Gain on Derivative
Intangible assets, Additions
Finite-Lived Intangible Assets Acquired
Defined Benefit Plans
Retirement Plan Type [Domain]
Total current liabilities
Current liabilities
Liabilities, Current
Regulatory assets, non-current
Regulatory Asset, Noncurrent
Unrealized Gain Losses On Cash Flow Hedging Instruments
Unrealized gain losses on cash flow hedging instruments.
Arkansas Public Service Commission
Arkansas Public Service Commission [Member]
Arkansas Public Service Commission
Costs and Expenses, Direct
Costs and expenses, direct.
Operations and maintenance - Direct
Interest payments on Long-term debt.
Interest Payments on Long-term Debt [Member]
Interest Payments on Long-term Debt
Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity [Abstract]
Adjustments to reconcile net income to net cash provided by operating activities:
Long-term Purchase Commitment
Long-Term Purchase Commitment [Table Text Block]
Hedging Designation [Domain]
Hedging Designation [Domain]
Income Tax Reconciliation Regulatory Percentage [Abstract]
Income tax reconciliation regulatory percentage.
Regulatory
First Mortgage Bonds Due 2044
First Mortgage Bonds Due 2044 [Member]
First Mortgage Bonds Due 2044 [Member]
Income Tax Paid, Federal, after Refund Received
Total Federal
Schedule of Guarantor Obligations
Schedule of Guarantor Obligations [Table Text Block]
Effective Income Tax Rate Reconciliation, Flow Through Accounting
The portion of the difference between the effective income tax rate and domestic federal statutory income tax rate that can be explained by Flow Through Accounting.
Flow-through adjustments, percent
Effective Income Tax Rate Reconciliation, Tax Credit, Percent [Abstract]
Tax credits
Effective Income Tax Rate Reconciliation, Tax Credit, Other, Amount
Other
Other
Additions for prior year tax positions
Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions
Defined Contribution Plan, Company Retirement
Defined Contribution Plan, Company Retirement [Member]
The Company Retirement portion of the defined contribution plan in which there is no employee contribtuion required to receive a contribution. The contribution is based on a calculation of age and service. [Member]
Impairment of investment
Impairment of investment
Other Asset Impairment Charges
Public Utilities Amount of System Safety and Integrety Rider Moved to Base Rates
Public Utilities Amount of System Safety and Integrety Rider Moved to Base Rates
Public Utilities Amount of System Safety and Integrety Rider Moved to Base Rates
Consolidation Items [Domain]
Consolidation Items [Domain]
Senior Unsecured Notes Due 2023
Senior Unsecured Notes Due 2023 [Member]
Senior Unsecured Notes Due 2023 [Member]
Asset Retirement Obligations [Table]
Asset Retirement Obligations [Table]
Asset Retirement Obligations [Table]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification,Tax (Benefit)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, Tax
Derivative, Nonmonetary Notional Amount
Derivative, Nonmonetary Notional Amount
Equity:
Equity, Attributable to Parent [Abstract]
COLORADO
Colorado
Entity Small Business
Entity Small Business
Regulated Operations [Abstract]
Regulated Operations [Abstract]
Contract or notional amounts and terms of marketing activities and derivative commodity instruments
Schedule of Notional Amounts of Outstanding Derivative Positions [Table Text Block]
Hedging Designation [Axis]
Hedging Designation [Axis]
Commodity derivatives
Commodity Contract
Commodity Contract [Member]
Retained earnings
Retained Earnings (Accumulated Deficit)
Retained Earnings (Accumulated Deficit), Total
Funded status - deficiency
Defined Benefit Plan, Funded (Unfunded) Status of Plan
Defined Benefit Plan, Funded (Unfunded) Status of Plan, Total
At The Market Equity Offering Program [Line Items]
At The Market Equity Offering Program [Line Items]
Costs and Expenses Allocated
Costs and expenses allocated.
Operations and maintenance - Allocated
Entity Well-known Seasoned Issuer
Entity Well-known Seasoned Issuer
Effective Income Tax Rate Reconciliation Changes In Unrecognized Tax Benefits Percentage
Effective income tax rate reconciliation changes in unrecognized tax benefits percentage.
Changes in Unrecognized Tax Benefits, percent
Transfers of production tax credits to third party
Transfers of Production Tax Credits to Third Party
Transfers of production tax credits to third party.
Settled Litigation [Member]
Share-based Compensation Plans
Share-Based Payment Arrangement [Text Block]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Dividends paid on common stock
Payments of Dividends
Payments of Dividends, Total
Senior Unsecured Notes Due 2035 [Member]
Senior unsecured notes due 2035.
Senior Unsecured Notes Due 2035
Senior Unsecured Notes Due 2035 [Member]
First Mortgage Bonds Due 2037
First Mortgage Bonds Due 2037 [Member]
First Mortgage Bonds Due 2037 [Member]
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset
Derivative Liability, Subject to Master Netting Arrangement, Gross Asset and Collateral, Right to Reclaim Cash, Offset
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset, Total
Amendment Flag
Amendment Flag
Taxes, Miscellaneous
Taxes, Miscellaneous, Total
Taxes other than income taxes
Taxes other than income taxes
Product and Service [Domain]
Product and Service [Domain]
Loss Contingencies [Line Items]
Loss Contingencies [Line Items]
Allowance for Funds Used During Construction, Capitalized Interest
AFUDC Debt
Effective Income Tax Rate Reconciliation at Federal Statutory Income Tax Rate, Amount
U.S. Federal statutory rate
Employee benefit plans and related deferred taxes
Employee benefit plans and related deferred taxes liabilities.
Employee Benefit Plans And Related Deferred Taxes Liabilities [Member]
Dividend Reinvestment Plan
Dividend Reinvestment and Stock Purchase Plan [Member]
Dividend Reinvestment and Stock Purchase Plan [Member]
Business Description and Significant Accounting Policies
Organization, Consolidation, Basis of Presentation, Business Description and Accounting Policies [Text Block]
Regulatory Asset [Line Items]
Earnings per Share of Common Stock
Earnings Per Share, Policy [Policy Text Block]
LIABILITIES AND EQUITY
Liabilities and Equity [Abstract]
Entity Address, Postal Zip Code
Entity Address, Postal Zip Code
Accounts Receivable and Allowance for Credit Losses
Accounts Receivable [Policy Text Block]
Cash Provided by (Used in) Operating Activity, Including Discontinued Operation
Net cash provided by operating activities
GSRS Rider Revenue [Member]
GSRS Rider Revenue.
GSRS Rider Revenue
Segment Reporting, CODM, Profit (Loss) Measure, How Used, Description
Common Stock [Member]
Common Stock
Accumulated benefit obligation at end of year
Defined Benefit Plan, Accumulated Benefit Obligation
Defined Benefit Plan, Accumulated Benefit Obligation
Electric Generation Capacity, Megawatts
Number of Megawatts Capacity Purchased - old
Number of Megawatts being purchased under capacity and energy contract
Tax Credit Carryforward, Amount
Tax Credit Carryforward
Defined Contribution Plan, Employer Discretionary Contribution Amount
Defined Contribution Plan, Employer Discretionary Contribution Amount
Long-Term Debt, Maturity, Year One
2026
Black Hills Energy - Colorado Electric
Black Hills Energy - Colorado Electric [Member]
Black Hills Energy - Colorado Electric
Hedging Relationship [Domain]
Hedging Relationship [Domain]
Schedule of Health Care Cost Trend Rates
Schedule of Health Care Cost Trend Rates [Table Text Block]
Assets for Plan Benefits, Defined Benefit Plan
Non-current assets
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Total
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Beginning Balance
Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Ending Balance
Less accumulated depreciation and depletion
Less accumulated depreciation
Less accumulated depreciation
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]
June 16, 2023 ATM Program
June Sixteen Twenty Twenty Three ATM Program [Member]
June 16, 2023 ATM program.
Supplemental Employee Retirement Plan
Supplemental Employee Retirement Plan [Member]
Supplemental Plans
Surety Bond
Surety Bond [Member]
At The Market Equity Offering Program [Table]
At The Market Equity Offering Program.
Portion at Fair Value Measurement
Portion at Fair Value Measurement [Member]
Portion at Fair Value Measurement [Member] [Default]
Performance Share Units - Market Condition
Performance Share Units - Market Condition [Member]
Performance Share Units - Market Condition
Entity Address, Address Line One
Entity Address, Address Line One
Total deferred tax liabilities
Deferred Tax Liabilities, Gross
Deferred Tax Liabilities, Gross, Total
Public Utilities, Approved Return on Equity, Percentage
Public Utilities, Approved Return on Equity, Percentage
Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions
Schedule of Share-Based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]
Fair Value Hierarchy and NAV [Axis]
Fair Value Hierarchy and NAV [Axis]
Earnings per share of common stock:
Earnings Per Share [Abstract]
Income Taxes
Income Tax, Policy [Policy Text Block]
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Flag]
Supplemental cash flow information:
Supplemental Cash Flow Information [Abstract]
Derivative Assets, Fair Value Disclosure
Derivative Asset
Derivative Asset, Total
Gas distribution
Gas Distribution Equipment [Member]
Wyoming Electric
Wyoming Electric [Member]
Wyoming Electric [Member]
Loss Contingency [Abstract]
Defined Benefit Plan, Expected Future Benefit Payment, Year Four
2029
Balance Sheet Location [Axis]
Statement of Financial Position Location, Balance [Axis]
Insurance Recovery Assets
Insurance recovery assets.
Insurance recovery asset
Defined Benefit Plan, Plan Assets, Category [Domain]
Defined Benefit Plan, Plan Assets, Category [Domain]
Cybersecurity Risk Board Committee or Subcommittee Responsible for Oversight [Text Block]
Effective Income Tax Rate Reconciliation, State and Local Jurisdiction, Contribution Greater than 50 Percent, Tax Effect [Extensible Enumeration]
Net income attributable to non-controlling interest
Less: comprehensive income attributable to non-controlling interest
Net Income (Loss) Attributable to Noncontrolling Interest
Net Income (Loss) Attributable to Noncontrolling Interest, Total
Deferred energy and fuel cost adjustments
Deferred Energy and Fuel Cost Adjustments [Member]
Deferred energy and fuel cost adjustments.
Contract Subject to Master Netting Arrangement [Member]
Contract Subject to Master Netting Arrangement [Member]
Contract Subject to Master Netting
Document Type
Document Type
Basis Swap [Member]
Natural gas basis swaps purchased
Goodwill and Intangible Assets
Goodwill and Intangible Assets, Policy [Policy Text Block]
WPSC Approved a Settlement Agreement for a General Rate Increase
WPSC Approved a Settlement Agreement for a General Rate Increase [Member]
WPSC approved a settlement agreement for a general rate increase.
Income Taxes Paid, Net
Income taxes net of transferred tax credits (Note 15)
Total income taxes (paid) received
Total income taxes (paid) received
Entity Central Index Key
Entity Central Index Key
Accounts Receivable, Allowance for Credit Loss, Current
Less Allowance for Credit Losses
Balance at End of Year
Balance at Beginning of Year
Line of Credit Facility [Table]
Public Utilities - Length of Electric Distribution Lines to Receive Infrastructure Investments
Public Utilities - Length of Electric Distribution Lines to Receive Infrastructure Investments
Public Utilities - Length of Electric Distribution Lines to Receive Infrastructure Investments
Debt Securities, Available-for-Sale [Table Text Block]
Schedule of Fair Value of Investments in Equity Securities
Cybersecurity Risk Process for Informing Board Committee or Subcommittee Responsible for Oversight [Text Block]
Other assets:
Other Assets, Noncurrent [Abstract]
Net change in cash, restricted cash and cash equivalents
Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Period Increase (Decrease), Excluding Exchange Rate Effect, Including Discontinued Operation
Subsequent Event Type [Domain]
Subsequent Event Type [Domain]
Black Hills Energy - Iowa Gas
Black Hills Energy - Iowa Gas [Member]
Black Hills Energy - Iowa Gas
Amendments
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment
Plant acquisition adjustment
Plant Acquisition Adjustment [Member]
Plant Acquisition Costs
Common stock, par value (usd per share)
Common Stock, Par or Stated Value Per Share
Regulatory Accounting
Public Utilities, Policy [Policy Text Block]
Base Rate
Base Rate [Member]
Goodwill [Line Items]
Goodwill [Line Items]
Rule 10b5-1 Arr Modified [Flag]
Rule 10b5-1 arr modified flag.
Volatility range for the peer group, Maximum
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum
Total plant in service before construction work in progress
Public Utilities, Property, Plant and Equipment Excluding Construction in Progress
Public Utilities, Property, Plant and Equipment Excluding Construction in Progress
Number Of One-Year Extension Options
Number Of One-Year Extension Options
Number Of One-Year Extension Options
Document Financial Statement Error Correction [Flag]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Reclassification Adjustment out of Accumulated Other Comprehensive Income on Derivatives [Line Items]
Debt Covenants [Abstract]
Debt Disclosure [Abstract]
Other regulatory assets
Other Regulatory Assets [Member]
Other regulatory assets [Member]
Derivative [Table]
Derivative [Table]
State income tax expense (benefit)
State and Local Income Tax Expense (Benefit), Continuing Operations
State and Local Income Tax Expense (Benefit), Continuing Operations, Total
Federal Energy Regulatory Commission (FERC)
Federal Energy Regulatory Commission (FERC) [Member]
Federal Energy Regulatory Commission (FERC) [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Reclassification out of Accumulated Other Comprehensive Income [Axis]
Reclassification out of Accumulated Other Comprehensive Income [Axis]
Schedule of Regulatory Assets and Liabilities
Schedule of Regulatory Assets and Liabilities [Table Text Block]
Schedule of Regulatory Assets and Liabilities
At The Market Equity Offering Program, Aggregate Gross Sales Price Limitation Value
At the market equity offering program, aggregate gross sales price limitation value.
Fair Value
Fair Value
Estimate of Fair Value Measurement [Member]
Gas Utilities
Gas Utilities [Member]
Gas Utilities [Member]
Accrued liabilities
Total accrued liabilities
Accrued Liabilities, Current
Fuel, purchased power and cost of natural gas sold
Cost of Sales [Member]
Current Fiscal Year End Date
Current Fiscal Year End Date
Investment income (loss)
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Actual Return (Loss)
Schedule of Long-term Debt Instruments [Table]
Schedule of Long-Term Debt Instruments [Table]
Distributions to non-controlling interests
Payments to Noncontrolling Interests
Target shares, value
Employee Service Share-based Compensation, Other Than Options, Total Payout Value
The amount of the total payout for an employee service share-based compensation award for other than options that has been accrued at the Balance Sheet date. The total value includes the stock price, dividends and the percentage payout value.
Error Correction, Type [Axis]
Error Correction, Type [Axis]
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures, Total
Assets relating to captive insurance
Regulatory Liability [Domain]
Regulatory Liability [Domain]
Global Settlement agreement with KCC Staff and various intervenors for a general rate increase and renewal of its safety and integrity rider.
Global Settlement agreement with KCC Staff and various intervenors for a general rate increase and renewal of its safety and integrity rider. [Member]
Global Settlement agreement with KCC Staff and various intervenors for a general rate increase and renewal of its safety and integrity rider.
Litigation Case [Domain]
Unrecorded Unconditional Purchase Obligation [Line Items]
Unrecorded Unconditional Purchase Obligation [Line Items]
Timing of Transfer of Good or Service [Axis]
Timing of Transfer of Good or Service [Axis]
Entity Address, State or Province
Entity Address, State or Province
Public Utilities, Term Extension of System Saftey and Integrity Rider
Public Utilities, Term Extension of System Saftey and Integrity Rider
Public Utilities, Term Extension of System Saftey and Integrity Rider
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Beginning Balance
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance
Production, Electric
Electric Generation Equipment [Member]
Collateral Already Posted, Aggregate Fair Value
Credit Risk Derivative Liabilities, at Fair Value
Loss Contingency, Concession Award, Area
Loss Contingency, Concession Award, Area
Loss Contingency, Concession Award, Area
Preferred Stock, Shares Outstanding
Preferred Stock, Shares Outstanding
Preferred Stock, Shares Outstanding, Beginning Balance
Preferred Stock, Shares Outstanding, Ending Balance
Comprehensive income available for common stock
Comprehensive Income (Loss), Net of Tax, Attributable to Parent
Public Utilities - Length of Natural Gas Pipeline to Receive Infrastructure Investments
Public Utilities - Length of Natural Gas Pipeline to Receive Infrastructure Investments
Public Utilities - Length of Natural Gas Pipeline to Receive Infrastructure Investments
Unissued Shares Available
Common Stock, Capital Shares Reserved for Future Issuance
Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements
Dilutive effect of equity compensation
Schedule of Assumptions Used
Defined Benefit Plan, Assumptions [Table Text Block]
Geographical [Axis]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligation Disclosure [Abstract]
Fuel, purchased power and cost of natural gas sold
Fuel, purchased power and cost of natural gas sold
Fuel, Purchased Power and Cost of Gas Sold
Fuel costs incurred that are directly related to goods produced and sold and services rendered during the reporting period, combined with the amount of purchased power charged against earnings for the period, and cost of gas sold to customers for the period.
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration]
Cushion gas - not depreciable
Cushion Gas - Not Depreciated [Member]
Cushion Gas - Not Depreciated [Member]
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount
State and local income taxes, net of federal income tax effect
Share-based Payment Arrangement, Expensed Amount
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Amount
Other
(Tax) benefit on benefit plan liability adjustments - prior service costs
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Tax
Tax Credit Carryforward, Valuation Allowance
Income Tax Credit carryforward, valuation allowance
Schedule of Deferred Tax Assets and Liabilities
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]
Other comprehensive income (loss), net of tax:
Other Comprehensive Income (Loss), Net of Tax [Abstract]
Performance Shares
Performance Shares [Member]
Market - off-system sales
Market Off-System Sales [Member]
Market Off-System Sales [Member]
Energy Related Derivative
Energy Related Derivative [Member]
Black Hills Energy, Kansas Gas
Black Hills Energy, Kansas Gas [Member]
Black Hills Energy, Kansas Gas
Other Postretirement Benefits Plan
Other Postretirement Benefits Plan [Member]
Healthcare Plan
Subsequent Event
Subsequent Event [Member]
Amounts reclassified from AOCI
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment [Abstract]
Other assets, non-current
Other Assets, Noncurrent
Changes in Unrecognized Tax Benefits
Effective Income Tax Rate Reconciliation Changes In Unrecognized Tax Benefits Amount
Effective income tax rate reconciliation changes in unrecognized tax benefits amount.
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards [Line Items]
Black Hills Wyoming and Wyodak Resources Development Corporation
Black Hills Wyoming and Wyodak Resources Development Corporation [Member]
Black Hills Wyoming and Wyodak Resources Development Corporation.
Restricted Stock and RSUs, total fair value of shares vested
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value
External Customers
External Customers [Member]
External Customers
Less unamortized debt discount
Debt Instrument, Unamortized Discount
Debt Instrument, Unamortized Discount, Total
State and Local Jurisdiction
State and Local Jurisdiction [Member]
Regulatory Asset, Amortization Period
Regulatory Asset, Amortization Period
Derivative, Loss, Statement of Income or Comprehensive Income [Extensible Enumeration]
Related Party Transaction [Axis]
Related Party Transaction [Axis]
Accumulated Other Comprehensive Income (Loss)
AOCI Attributable to Parent [Member]
Customer [Domain]
Customer [Domain]
Derivative, Liabilities, Fair Value Disclosure
Derivative Liability
Derivative Liability, Total
Return Seeking Assets
Return Seeking Assets [Member]
Return Seeking Assets - Consisting of Equity Securities, Real Estate, Fixed Income Funds and Cash
Treasury stock, shares
Treasury Stock, Common, Shares
Ending balance (in shares)
Beginning balance (in shares)
Deferred Financing Costs
Deferred Financing Costs [Table Text Block]
Schedule of Deferred Financing Costs expensed on the Statement of Income and/or net amount presented on the Statement of Financial Position [Table Text Block]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Regulatory liabilities
Deferred Tax Assets, Regulatory Assets and Liabilities
Unrecorded Unconditional Purchase Obligations Disclosure
Unrecorded Unconditional Purchase Obligations Disclosure [Table Text Block]
Net (gain) loss
Accumulated Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Tax
Lessor, Lease, Description [Table]
Lessor, Lease, Description [Table]
Deferred:
Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract]
Prepayment penalty
Payment for Debt Extinguishment or Debt Prepayment Cost
Reclassification out of Accumulated Other Comprehensive Income [Domain]
Reclassification out of Accumulated Other Comprehensive Income [Domain]
Debt Instrument, Maturity Date
Long term debt maturity date
Derivative, Loss on Derivative
Derivative, Loss on Derivative
Settlement agreement reached with CPUC Staff and various intervenors, subject to the review and approval by an Administrative Law Judge and the CPUC.
Settlement agreement reached with CPUC Staff and various intervenors, subject to the review and approval by an Administrative Law Judge and the CPUC. [Member]
Settlement agreement reached with CPUC Staff and various intervenors, subject to the review and approval by an Administrative Law Judge and the CPUC.
Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months
Cash Flow Hedge Gain (Loss) to be Reclassified within 12 Months
Minimum
Minimum [Member]
May Eight Two Thousand Twenty Five Atm Program [Member]
May 8, 2025 ATM Program.
May 8, 2025 ATM Program
Granted (usd per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value
Financial Instrument [Axis]
Derivative Asset, Fair Value, Gross Asset
Derivative Asset, Subject to Master Netting Arrangement, before Offset
Current assets:
Assets, Current [Abstract]
Real Estate [Member]
Real Estate
Public Utilities, Requested Term Extension of System Safety and Integrity Rider
Public Utilities, Requested Term Extension of System Safety and Integrity Rider
Public Utilities, Requested Term Extension of System Safety and Integrity Rider
Capital Expenditures
Property, Plant and Equipment, Gross, Period Increase (Decrease)
Property, Plant and Equipment, Gross, Period Increase (Decrease), Total
Intangible assets, amortization expense
Amortization of Intangible Assets
Fair Value, Inputs, Level 3
Fair Value, Inputs, Level 3 [Member]
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Inter-segment
Inter Segment Revenues [Member]
Inter segment revenues.
Other deferred credits and other liabilities
Derivative Liabilities, Noncurrent
Derivative Liabilities, Noncurrent [Member]
Line item in the statement of financial position in a classified presentation in which the fair value amounts of the derivative instruments are included.
Schedule of Unit Contingent Capacity
Schedule of Unit Contingent Capacity [Table Text Block]
[Table Text Block] for Schedule of Unit Contingent Capacity [Table]
Accelerated depreciation, amortization and other plant-related differences
Deferred Tax Liabilities, Property, Plant and Equipment
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]
Schedule of Fair Value Hierarchy, Measured on Recurring Basis
Public Utilities, Requested Return on Equity, Percentage
Public Utilities, Requested Return on Equity, Percentage
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Cash Flow Hedging
Current liabilities:
Liabilities, Current [Abstract]
Long-term Contract for Purchase of Electric Power [Domain]
Long-Term Contract for Purchase of Electric Power [Domain]
Regulatory Asset [Axis]
Regulatory Asset [Axis]
Commercial Paper, Maximum Borrowing Capacity
Commercial Paper, Maximum Borrowing Capacity
Commercial Paper, Maximum Borrowing Capacity
Senior Unsecured Notes Due 2029 [Member]
Senior Unsecured Notes Due 2029 [Member]
Senior Unsecured Notes Due 2029
Lessor, Operating Lease, Payment to be Received, Fiscal Year Maturity
Lessor, Operating Lease, Payment to be Received, Maturity [Table Text Block]
Senior Unsecured Notes Due 2033
Senior Unsecured Notes Due 2033 [Member]
Senior Unsecured Notes Due 2033 [Member]
Operating Loss Carryforwards
Operating Loss Carryforwards
Accounts receivable, net
Accounts Receivable, after Allowance for Credit Loss, Current
Accounts Receivable, net
Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]
Account Receivable Schedule
Regulatory liabilities, current
Regulatory liabilities, current
Regulatory Liability, Current
Debt Issuance Cost, Gross, Noncurrent
Debt Issuance Cost, Gross, Noncurrent
Operations and maintenance
Operating Expense, Maintenance, Operations, and Other Costs and Expense
Amount of operating expenses for the period including selling, general, and administrative expenses, costs include routine repairs and maintenance and operations.
Commitments, contingencies and guarantees (Note 3)
Commitments and Contingencies
Defined Benefit Plan Assumptions Used In Calculating Net Periodic Benefit Cost Expected Rate of Return On Assets For Next Fiscal Year
Defined Benefit Plan Assumptions Used In Calculating Net Periodic Benefit Cost Expected Rate of Return On Assets For Next Fiscal Year
An assumption for the next fiscal year as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation
Service Cost
Defined Benefit Plan, Service Cost
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value, Beginning Balance
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value, Ending Balance
Reclassification out of Accumulated Other Comprehensive Income [Table]
Reclassification out of Accumulated Other Comprehensive Income [Table]
(Tax) benefit on benefit plan liability adjustments - net gain (loss)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax
Eurodollar [Member]
Eurodollar
Share-based compensation (in shares)
Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture
Shares Issued, Shares, Share-Based Payment Arrangement, after Forfeiture, Total
Additions Charged to Costs and Expenses
Accounts Receivable, Credit Loss Expense (Reversal)
Iowa Utilities Board (IUB)
Iowa Utilities Board (IUB) [Member]
Iowa Utilities Board (IUB)
Auditor Firm ID
Auditor Firm ID
Net borrowings (payments) of Revolving Credit Facility and CP Program
Net borrowings (payments) of Revolving Credit Facility and CP Program
Net borrowings (payments) of Revolving Credit Facility and CP Program
Accounts Receivable, before Allowance for Credit Loss, Current
Billed Accounts Receivable
Scenario Forecast
Forecast [Member]
Natural gas physical commitments, net
Natural Gas Physical Purchases [Member]
Natural Gas Physical Purchases [Member]
Notes payable
Short-Term Debt
Short-Term Debt, Total
Amount outstanding
Goodwill
Schedule of Goodwill [Table Text Block]
Income Tax Reconciliation Regulatory Amount [Abstract]
Income tax reconciliation regulatory amount.
Regulatory
Materials and supplies
Inventory, Raw Materials and Supplies, Gross
Inventory, Raw Materials and Supplies, Gross, Total
Defined Contribution Plan, 401K
Defined Contribution Plan, 401K [Member]
The 401K defined contribution plan, which requires a contribution from the employee in order to receive a matching contribution (within limits) from the employer [Member]
Commodity Option [Member]
Natural gas options purchased, net
Category of Item Purchased [Axis]
Category of Item Purchased [Axis]
Settlement Reached with the Regulatory Agency
Settlement Reached with the Regulatory Agency [Member]
Settlement Reached with the Regulatory Agency
Investment Objective [Axis]
Long-Term Debt, Maturity, Year Two
2027
Variable Interest Entity, Primary Beneficiary
Variable Interest Entity, Primary Beneficiary [Member]
Effective Income Tax Rate Reconciliation Flow Through Accounting Amount
Effective income tax rate reconciliation flow through accounting amount.
Flow-through adjustments
Deferred credits and other liabilities:
Liabilities, Noncurrent [Abstract]
Accrued property, plant and equipment purchases at December 31
Capital Expenditures Incurred but Not yet Paid
Net income
Net income
Net income
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest
Summary of ATM Activity
Summary of at-the-marke activity.
Summary of At-the-Marke Activity [Table Text Block]
Segment information included in Consolidated Balance Sheets
Reconciliation of Assets from Segment to Consolidated [Table Text Block]
Long-Term Debt, Type [Domain]
Cybersecurity Risk Management Positions or Committees Responsible [Text Block]
Loss Contingencies [Table]
Loss Contingencies [Table]
Jointly Owned Utility Plant Interests [Line Items]
Jointly Owned Utility Plant Interests [Line Items]
Weighted average shares - Basic (in shares)
Basic (in shares)
Weighted Average Number of Shares Outstanding, Basic
Weighted Average Number of Shares Outstanding, Basic, Total
Unrecorded Unconditional Purchase Obligation, to be Paid, Year One
2026
Investment Objective [Domain]
Scenario [Axis]
Deferred gas cost adjustments
Asset Recoverable Gas Costs [Member]
Regulatory assets
Regulatory assets
Regulatory Asset
Recovery of incremental costs
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Other
Stockholders' Equity, Other
Schedule of Effective Income Tax Rate Reconciliation
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]
Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table]
Schedule of Share-Based Compensation Arrangements by Share-Based Payment Award [Table]
Segments [Axis]
Segments [Axis]
Property, Plant and Equipment, Type [Domain]
Long-Lived Tangible Asset [Domain]
Liabilities Incurred
Asset Retirement Obligation, Liabilities Incurred
Contingent Capacity Amounts on Wygen III
Wygen III Generating Facility
Wygen III Generating Facility [Member]
Wygen III - Black Hills Power's coal-fired power generation plant that commenced operations on April 1, 2010.[Member]
Cybersecurity Risk Process for Informing Management or Committees Responsible [Text Block]
Schedule of Short-term Debt
Schedule of Short-Term Debt [Table Text Block]
Deferred Tax Assets, Net [Abstract]
Deferred Tax Assets, Net [Abstract]
Subsequent Events
Subsequent Events [Text Block]
At the market equity offering program average price per share.
At The Market Equity Offering Program Average Price Per Share
Average price per share
Direct Payments Net of Refunds [Member]
Direct Payments Net of Refunds.
Direct Payments Net of Refunds
Long-term debt, including current maturities
Long-Term Debt
Long-Term Debt, Total
Total
Black Hills Energy - Wyoming Gas
Black Hills Energy Wyoming Gas [Member]
Black Hills Energy Wyoming Gas.
Variable Rate [Domain]
Variable Rate [Domain]
Actuarial (gain) loss
Defined Benefit Plan, Benefit Obligation, Actuarial Gain (Loss)
Total stockholders’ equity
Equity, Attributable to Parent
Stockholders' Equity Attributable to Parent, Beginning Balance
Stockholders' Equity Attributable to Parent, Ending Balance
General
Public Utilities, Property, Plant and Equipment, Other Property, Plant and Equipment
Unrecorded Unconditional Purchase Obligation, to be Paid, Year Five
2030
Schedule of Variable Interest Entities
Schedule of Variable Interest Entities [Table Text Block]
Statement of Stockholders' Equity [Abstract]
Credit Facility and Short Term Debt Covenants
Credit Facility and Short Term Debt Covenants [Table Text Block]
Credit Facility and Short Term Debt Covenants
Colorado Public Utilities Commission (CPUC)
Colorado Public Utilities Commission (CPUC) [Member]
Colorado Public Utilities Commission (CPUC) [Member]
Arkansas
ARKANSAS
Hedge Funds
Hedge Funds, Multi-strategy [Member]
Liability-hedging Assets
Use of Estimates and Basis of Presentation
Use of Estimates, Policy [Policy Text Block]
Schedule of Nonvested Share Activity
Schedule of Nonvested Share Activity [Table Text Block]
Schedule of Jointly Owned Utility Plants
Schedule Of Jointly Owned Facilities [Table Text Block]
Tabular disclosure of proportionate interests in jointly owned plants. Includes the amount of plants in service, the accumulated provision for depreciation (if available), the amount of facilities under construction, and the proportionate share. Includes statements that the amounts represent the company's share in each joint plant and that it must provide its own financing. Information concerning two or more plants on the same site may be combined. States that the company's share of direct expenses of the joint facilities is included in the corresponding operating expenses on its income statement (for example, maintenance and other operating expense). This schedule includes both Utility and non-Utility facilities. [Table Text Block]
Treasury Stock
Treasury Stock, Common [Member]
Long-Term Debt, Maturity, Year Five
2030
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Disclosure [Line Items]
Public Utilities Approved Shift Rate Rider Rate to Base Rate
Public utilities approved shift rate rider rate to base rate.
Public Utilities, Approved Shift Rate Rider Rate to Base Rate
Other regulatory liabilities
Other Regulatory Liabilities [Member]
Other regulatory liabilities [Member]
Public Utilities, Regulatory Proceeding [Domain]
Public Utilities, Regulatory Proceeding [Domain]
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award
Disclosure of Share-Based Compensation Arrangements by Share-Based Payment Award [Table Text Block]
Kansas Corporation Commission (KCC)
Kansas Corporation Commission (KCC) [Member]
Kansas Corporation Commission (KCC)
Accumulated Defined Benefit Plans Adjustment
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Deferred taxes on AFUDC
Allowance For Funds Used During Construction [Member]
The offsetting entry to other income when an enterprise capitalizes, as part of the cost of plant and equipment, the cost of financing construction as financed partially by equity.
Busch Ranch I Wind Farm
Busch Ranch I Wind Farm [Member]
Busch Ranch I Wind Farm [Member]
Electric Generation Capacity, Megawatts
Number of Megawatts being purchased under capacity and energy contract.
Number of Megawatts Capacity Purchased
Number of Megawatts Capacity Purchased
Noncontrolling Interest
Noncontrolling Interest [Member]
Percentage of Healthcare Plan Assets Invested
Percentage of healthcare plan assets invested.
Percentage of healthcare plan assets invested
Schedule of Accrued Liabilities
Schedule of Accrued Liabilities [Table Text Block]
Debt Instrument, Name [Domain]
Debt Instrument, Name [Domain]
Regulatory Assets [Domain]
Regulatory Asset [Domain]
Guarantor Obligations [Line Items]
Guarantor Obligations [Line Items]
Other current assets
Other Assets, Current
Long-Term Debt, Maturity, Year Four
2029
Principal payments on long-term debt including current maturities.
Principal Payments On Long-term Debt Including Current Maturities [Member]
Principal Payments on Long-term Debt Including Current Maturities
Power Purchase Agreements [Member]
Power Purchase Agreements [Member]
PPAs
Environmental
Environmental [Member]
Environmental costs associated with utility property [Member]
Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]
Reconciliation of Unrecognized Tax Benefits
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Segment Reporting, CODM, Individual Title and Position or Group Name [Extensible Enumeration]
Loss Contingency, Damages Awarded, Value
Retail Customers Incremental Rate Limited Percentage
Retail customers incremental rate limited percentage.
Retail customers incremental rate limited percentage
Plan Name [Domain]
Plan Name [Domain]
Rate Review Filed with the Regulatory Agency
Rate Review Filed with the Regulatory Agency [Member]
Rate Review Filed with the Regulatory Agency [Member]
Regulatory liabilities
Regulatory liabilities
Regulatory Liability
Asset Retirement Obligations
Asset Retirement Obligation Disclosure [Text Block]
Interest Expense, Operating and Nonoperating
Interest Expense, Total
Interest expense, net
Asset Retirement Obligation Costs [Line Items]
Asset Retirement Obligation Costs [Line Items]
Costs provided for the retirement of certain long-live assets that are reasonably expected to be recovered in utility rates charged to customers [Line Items]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Entity [Domain]
Entity [Domain]
Credit Facility [Axis]
Credit Facility [Axis]
Cybersecurity Risk Materially Affected or Reasonably Likely to Materially Affect Registrant [Text Block]
Income Taxes Paid (Received) [Table Text Block]
Income taxes paid (received).
Schedule of Income Taxes (Paid) Received
State
Current State and Local Tax Expense (Benefit)
Schedule of Expected Benefit Payments
Schedule of Expected Benefit Payments [Table Text Block]
Black Hills Service Company
Black Hills Service Company [Member]
Black Hills Service Company [Member]
Cybersecurity Risk Management Expertise of Management Responsible [Text Block]
Debt Securities [Member]
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year
Lessor, Operating Lease, Payment to be Received, Year Two
2027
Treasury Stock, Value
Treasury Stock, Value, Total
Treasury stock at cost - 43,167 and 56,608, respectively
Related Party [Axis]
Related and Nonrelated Parties [Axis]
Supply Commitment Arrangement [Domain]
Supply Commitment Arrangement [Domain]
Line of Credit Facility, Average Outstanding Amount
Average amount outstanding (based on daily outstanding balances)
Effective Income Tax Rate Reconciliation, Other Adjustments, Amount
Other
Transmission
Public Utilities, Property, Plant and Equipment, Transmission
Pension Plan
Pension Plan [Member]
Defined Benefit Pension Plans
Property, Plant and Equipment
Property, Plant and Equipment, Policy [Policy Text Block]
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), after Adjustments, Tax
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), after Adjustments, Tax, Total
Net unrealized gains (losses) on commodity derivatives (net of tax of $0.7, $0.1, and $1.1, respectively)
Effective Income Tax Rate Reconciliation, Tax Credit, Energy-Related, Percent
Energy-related tax credits, net of transferability discount, percent
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax
Benefit plan liability adjustments - net gain (loss) (net of tax of $0, $(0.2), and $0, respectively)
Entity Address, City or Town
Entity Address, City or Town
Black Hills Energy - Arkansas Gas
Black Hills Energy, Arkansas Gas [Member]
Black Hills Energy, Arkansas Gas
Colorado Renewable Energy [Member]
Colorado renewable energy.
Colorado renewable energy
Regulatory Matters
Schedule of Regulatory Assets and Liabilities [Text Block]
Operating Loss Carryforwards Valuation Allowance
Operating Loss Carryforwards, Valuation Allowance
Number of Reportable Segments
Number of reportable segments
(Tax) benefit on net unrealized gains (losses) on commodity derivatives
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), Adjustments, Tax
Subsidiary of Common Parent
Subsidiary of Common Parent [Member]
Security Exchange Name
Security Exchange Name
Credit Facility [Domain]
Credit Facility [Domain]
Regulatory Agency [Axis]
Regulatory Agency [Axis]
Long-term debt
Long-Term Debt, Gross
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent
Other, percent
Property, plant and equipment
Property, Plant and Equipment, Gross
Property, Plant and Equipment, Gross, Total
Property, Plant and Equipment, Gross, Beginning Balance
Property, Plant and Equipment, Gross, Ending Balance
Total gross property, plant and equipment
Liability for Unpaid Claims and Claims Adjustment Expense, Net
Liability for Unpaid Claims and Claims Adjustment Expense, Net, Ending Balance
Liability for Unpaid Claims and Claims Adjustment Expense, Net, Beginning Balance
IBNR claims reserve
Current:
Current Income Tax Expense (Benefit), Continuing Operations [Abstract]
Debt, Weighted Average Interest Rate
Debt, Weighted Average Interest Rate
Weighted average interest rates
Property, Plant and Equipment (AFUDC)
Public Utilities General Disclosures [Table Text Block]
Inter-segment Eliminations
Intersegment Eliminations [Member]
Commitments, Contingencies and Guarantees
Commitments Contingencies and Guarantees [Text Block]
Senior Unsecured Notes Due 2028
Senior Unsecured Notes Due 2028 [Member]
Senior unsecured notes due 2028.
Income before income taxes
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest
Income before income taxes
Performance Plan Payouts
Performance Plan Payouts [Table Text Block]
[Table Text Block] for Performance Plan Payouts [Table]
Public Utilities, Approved Debt Capital Structure, Percentage
Public Utilities, Approved Debt Capital Structure, Percentage
Industrial Development Revenue Bonds Due 2027
Industrial Development Revenue Bonds Due 2027 [Member]
Industrial Development Revenue Bonds Due 2027 [Member]
Depreciation, depletion and amortization, remaining amortization period
Depreciation, Depletion And Amortization, Remaining Amortization Period
The depreciation, depletion or amortization period remaining on an asset.
Megawatts Sold Under Long-Term Contract
Number of Megawatts Sold Under Long-Term Contract
Number of Megawatts Sold Under Long-Term Contract
Stockholders' Equity Note [Abstract]
Stockholders' Equity Note [Abstract]
Wygen I Generating Facility
Wygen I Generating Facility [Member]
Jointly Owned Wygen I Generating Facility [Member]
Interest Rate Swap and Commodity Derivative
Interest Rate Swap and Commodity Derivative [Member]
Interest Rate Swap and Commodity Derivative
Black Hills Electric Generation and Colorado Electric
Black Hills Electric Generation and Colorado Electric [Member]
Black Hills Electric Generation and Colorado Electric [Member]
Total materials, supplies and fuel
Materials, supplies and fuel
Inventory, Net
SEC Schedule, 12-09, Valuation Allowance, Tax Credit Carryforward [Member]
Valuation Allowance, Income Tax Credit Carryforwards
Cash, restricted cash and cash equivalents beginning of year
Cash, restricted cash and cash equivalents end of year
Cash, Cash Equivalent, Restricted Cash, and Restricted Cash Equivalent, Continuing Operation
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Total
Interest (net of amounts capitalized)
Interest Paid, Excluding Capitalized Interest, Operating Activity
Measurement Basis [Axis]
Measurement Basis [Axis]
Statistical Measurement [Domain]
Statistical Measurement [Domain]
Restricted cash and equivalents
Restricted Cash and Investments, Current
Restricted Cash and Investments, Current, Total
Alternative revenue and other
Alternative Revenue and Other [Member]
Alternative revenue and other.
Total current assets
Current assets
Assets, Current
Document Period End Date
Document Period End Date
Extension period.
Extension period as per settlement agreement
Extension Period
Fair Value, Measurements, Fair Value Hierarchy [Domain]
Fair Value Hierarchy and NAV [Domain]
ICFR Auditor Attestation Flag
ICFR Auditor Attestation Flag
Jointly Owned Utility Plant Interests [Table]
Regulated Operation, Jointly Owned Utility Plant [Table]
Benefits paid
Defined Benefit Plan, Benefit Obligation, Benefits Paid
Long-term Purchase Commitment [Line Items]
Long-Term Purchase Commitment [Line Items]
First Mortgage Bonds Due 2039
First Mortgage Bonds Due 2039 [Member]
First Mortgage Bonds Due 2039 [Member]
Prior service cost (gain)
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), after Tax
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage
Defined Contribution Plan, Employers Matching Contribution, Annual Vesting Percentage
Statement of Financial Position [Abstract]
Statement of Financial Position [Abstract]
Debt and Equity Securities, Unrealized Gain
Debt and Equity Securities, Unrealized Gain
Total Unrealized Gains
Cumulative Effect, Period of Adoption, Adjustment
Cumulative Effect, Period of Adoption, Adjustment [Member]
Corporate Term Loan Due June 2021
Corporate Term Loan Due June 2021 [Member]
Corporate Term Loan Due June 2021 [Member]
Line of Credit
Line of Credit [Member]
Public Utilities, Regulatory Proceeding [Axis]
Public Utilities, Regulatory Proceeding [Axis]
Remaining tax expense related to increase in valuation allowance.
Remaining tax expense related to increase in valuation allowance
Environmental Remediation Site [Axis]
Environmental Remediation Site [Axis]
Reclassification out of Accumulated Other Comprehensive Income
Reclassification out of Accumulated Other Comprehensive Income [Member]
Weighted average cost of capital
Weighted Average Cost of Capital
Weighted Average Cost of Capital
Net deferred tax liability
Deferred Tax Liabilities, Net
Deferred Tax Liabilities, Net, Total
Retiree contributions
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant
(Tax) benefit on reclassification adjustment of benefit plan liability - net loss
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax, Total
Current Income Tax Expense (Benefit)
Current income tax benefit (expense)
Cybersecurity Risk Management, Strategy, and Governance [Line Items]
Common Collective Trust, Equity Fund
Common Collective Trust, Equity Fund [Member]
Common Collective Trust, Equity Fund [Member]
Common Collective Trust - Equity
Not Designated as Hedging Instrument
Not Designated as Hedging Instrument [Member]
Schedule of Change in Asset Retirement Obligation
Schedule of Change in Asset Retirement Obligation [Table Text Block]
Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table]
Energy [Domain]
Energy [Domain]
Financial Instruments [Domain]
Partnership
Deferred Tax Assets, Investments
Electric Utilities
Electric Utilities [Member]
Electric Utilities Segment [Member]
Valuation Allowance by Deferred Tax Asset [Axis]
Valuation Allowance by Deferred Tax Asset [Axis]
Gain on Business Interruption Insurance Recovery
Jointly Owned Utility Plant [Axis]
Jointly Owned Utility Plant [Axis]
Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Requisite Service Period
Utility Bond Issuance Costs recoverable over the life of the original issue, or if refinanced, over the life of the new issue[Member]
Loss on reacquired debt
Loss on reacquired debt [Member]
Derivative Liability, Statement of Financial Position [Extensible Enumeration]
Expected return on assets
Defined Benefit Plan, Expected Return (Loss) on Plan Assets
Jointly Owned Utility Plant [Domain]
Jointly Owned Utility Plant [Domain]
Income tax disclosure.
Income Tax Disclosure [Line Items]
Restricted Stock
Restricted Stock [Member]
Variable Rate [Axis]
Variable Rate [Axis]
At the market equity offering program, reset size of ATM value
At the market equity offering program, reset szie of ATM value.
Maximum amount outstanding (based on daily outstanding balances)
Line of Credit Facility, Maximum Amount Outstanding During Period
Weighted average shares - diluted (in shares)
Diluted (in shares)
Weighted Average Number of Shares Outstanding, Diluted
Entity File Number
Securities Act File Number
Settlement Reached With All Intervenors For A General Rate Increase Subject To Npsc Approval [Member]
Settlement reached with all intervenors for a general rate increase subject to npsc approval.
Settlement reached with all intervenors for a general rate increase, subject to NPSC approval [Member]
Derivative Instruments, Gain (Loss)
Derivative Instruments, Gain (Loss) [Table Text Block]
Cover [Abstract]
Volatility range for peer group, Minimum
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum
Payment for Other Postretirement Benefits
Payment for Pension and Other Postretirement Benefits
Outstanding Performance Share/Units
Outstanding Performance Share/Units [Member]
Outstanding performance share/units member.
Unrecorded Unconditional Purchase Obligation, to be Paid, Year Two
2027
Term of Evergreen Contracts
Unrecorded Unconditional Purchase Obligation, Term
Transmission services agreements.
Transmission Services Agreements [Member]
Transmission Services Agreements
Derivative, Gain, Statement of Income or Comprehensive Income [Extensible Enumeration]
Nebraska Publc Service Commission (NPSC)
Nebraska Publc Service Commission (NPSC) [Member]
Nebraska Publc Service Commission (NPSC)
Income Tax Reconciliation Regulatory Other Amount
Income tax reconciliation regulatory other amount.
Other
Cumulative Effect, Period of Adoption [Axis]
Cumulative Effect, Period of Adoption [Axis]
Performance Shares, Forfeited in Period
Shares Forfeited
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeited in Period
Performance Shares, Forfeited in Period
Decommissioning costs
Environmental Restoration Costs [Member]
Real Estate Funds
Real Estate Funds [Member]
Common Collective Trust - Real Estate
Iowa Utilities Commission (I U C) [Member]
Iowa Utilities Commission (IUC).
Iowa Utilities Commission (IUC)
Derivative, Gain (Loss) on Derivative, Net
Derivative, Gain (Loss) on Derivative, Net
Derivative, Gain (Loss) on Derivative, Net, Total
Deferred Tax Asset [Domain]
Deferred Tax Asset [Domain]
Income before income taxes
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest
Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest, Total
Scenario [Domain]
Public Utilities, General Disclosures [Line Items]
Public Utilities, General Disclosures [Line Items]
Number of Operating Segments
Number of operating segments
Sale of Stock [Domain]
Sale of Stock [Domain]
Guarantor Subsidiaries
Guarantor Subsidiaries [Member]
Timing of Transfer of Good or Service [Domain]
Timing of Transfer of Good or Service [Domain]
Business Segment Information
Segment Reporting Disclosure [Text Block]
Senior Unsecured Notes Due 2034 [Member]
Senior Unsecured Notes Due 2034
Senior unsecured notes due 2034.
Business Combination, Asset Acquisition, Transaction between Entities under Common Control, and Joint Venture Formation [Abstract]
Corporate, Non-Segment
Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]
Segment Reporting, Reconciling Item, Corporate Nonsegment [Member]
Performance Share Award Payout, Shares of Common Stock Percentage
Share Based Compensation Arrangement By Share Based Payment Award, Payout, Shares Percentage
Payout percentage for share based compensation to be issued in shares of common stock.
Subsequent Event [Table]
Subsequent Event [Table]
Loss Contingency, Receivable
Loss Contingency, Receivable, Ending Balance
Loss Contingency, Receivable, Beginning Balance
Loss Contingency, Receivable, Total
Insurance recovery receivable
Other deferred tax assets
Deferred Tax Assets, Other
Transmission Service Agreement
Transmission Service Agreement [Member]
Short-term Debt, Type [Domain]
Short-Term Debt, Type [Domain]
Plant acquisition adjustment
Public Utilities, Property, Plant and Equipment, Amount of Acquisition Adjustments
Share Based Compensation Arrangement By Share Based Payment Award - Performance Period Used to Estimate Expected Share Payout
Share Based Compensation Arrangement By Share Based Payment Award - Performance Period Used to Estimate Expected Share Payout
Share Based Compensation Arrangement By Share Based Payment Award - Performance Period Used to Estimate Expected Share Payout
Gas Price Derivatives - Term of Contract
Derivative, Term of Contract
Weighted average useful life
Property, Plant and Equipment, Useful Life
Short-term Debt, Type [Axis]
Short-Term Debt, Type [Axis]
Recently Issued and Adopted Accounting Standards
New Accounting Pronouncements, Policy [Policy Text Block]
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity
Share-Based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]
Derivative Instruments, Gain (Loss) [Table]
Derivative Instruments, Gain (Loss) [Table]
Senior Unsecured Notes Due 2026
Senior Unsecured Notes Due 2026 [Member]
Senior Unsecured Notes Due 2026 [Member]
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Other, Percent
Other, percent
Common Collective Trust, Money Market [Member]
Common collective trust, money market.
Common Collective Trust, Money Market
Award vesting period
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Period
General
Other Capitalized Property Plant and Equipment [Member]
Other Comprehensive Income
Comprehensive Income (Loss) Note [Text Block]
Derivative Assets, Noncurrent
Derivative Assets, Noncurrent [Member]
Line item in the statement of financial position in a classified presentation in which the fair value amounts of the derivative instruments are included.
Other assets, non-current
Public Utilities, Approved Equity Capital Structure, Percentage
Public Utilities, Approved Equity Capital Structure, Percentage
Jointly Owned Utility Plant, Proportionate Ownership Share
Jointly Owned Utility Plant, Proportionate Ownership Share
Ownership Interest
Liabilities Settled
Asset Retirement Obligation, Liabilities Settled
Tri-State Generation and Transmission Association
Tri-State Generation and Transmission Association [Member]
Tri-State Generation and Transmission Association
Carrying Amount
Reported Value Measurement [Member]
Post-65 Ultimate trend rate - Black Hills Corp
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate
Long-term debt - issuance
Proceeds from Issuance of Long-Term Debt
Proceeds from Issuance of Long-Term Debt, Total
Forfeited (usd per share)
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount
Share-Based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount
Unrecognized Tax Benefits, Interest Expense
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense, Total
Lessee, Operating Lease, Term of Contract
Lessee, Operating Lease, Term of Contract
Reportable Segment, Aggregation before Other Operating Segment [Member]
Reportable Segment, Aggregation before Other Operating Segment [Member]
Common stock, shares outstanding
Beginning balance (in shares)
Ending balance (in shares)
Common Stock, Shares, Outstanding
Storm Costs
Storm Costs [Member]
Depreciation and amortization
Depreciation, depletion and amortization
Depreciation, Depletion and Amortization
Depreciation, Depletion and Amortization, Total
Net amortization of prior service cost
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)
Performance Share Award, Percentage of Target
Share-based Compensation Arrangement by Share-based Payment Award, Payout, Percentage of Target
The percentage target for payout of equity compensation awards
Document Transition Report
Document Transition Report
Total operating expenses
Operating Expenses
Thereafter
Unrecorded Unconditional Purchase Obligation, to be Paid, after Year Five
Production, Gas
Gas Gathering and Processing Equipment [Member]
Litigation Status [Axis]
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]
Schedule of Components of Income Tax (Expense) Benefit
Natural Gas, Distribution
Natural Gas, Distribution [Member]
Natural Gas for distribution [Member]
Deferred Tax Assets, Operating Loss Carryforwards, State and Local
State NOL
Comprehensive income
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest
Non-current liabilities
Benefit plan liabilities
Liability, Defined Benefit Plan, Noncurrent
Liability, Defined Benefit Plan, Noncurrent, Total
Statement of Cash Flows [Abstract]
Statement of Cash Flows [Abstract]
Gas supply contract termination
Gas Supply Contract Termination [Member]
Gas Supply Contract Termination [Member]
Reclassification adjustment of benefit plan liability - prior service cost (net of tax of $0, $0, and $0, respectively)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax
Federal
Current Federal Tax Expense (Benefit)
Issuance of common stock
Stock Issued During Period, Value, New Issues
Derivative Asset, Statement of Financial Position [Extensible Enumeration]
Interest rate swaps
Interest Rate Swap
Interest Rate Swap [Member]
Pension and Other Postretirement Plans, Policy [Policy Text Block]
Pension and Other Retiree Plans
Audit Information [Abstract]
Audit Information [Abstract]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets [Line Items]
Rate Review Approved by Regulatory Agency
Rate Review Approved by Regulatory Agency [Member]
Rate Review Approved by Regulatory Agency
Unrecognized Tax Benefits that Would Impact Effective Tax Rate
Unrecognized Tax Benefits that Would Impact Effective Tax Rate
Other deferred tax liabilities
Deferred Tax Liabilities, Other
Cybersecurity Risk Management Processes Integrated [Text Block]
Investments
Investment [Table Text Block]
Net income available for common stock
Net income available for common stock
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax [Abstract]
Amounts recognized in AOCI, net of tax as of December 31:
Black Hills Energy, Rocky Mountain Natural Gas
Black Hills Energy, Rocky Mountain Natural Gas [Member]
Rocky Mountain Natural Gas
Materials, supplies and fuel
Increase (Decrease) in Inventories
Increase (Decrease) in Inventories, Total
Fuel
Energy Related Inventory, Other Fossil Fuel
Non Rule 10b51 Arr Modified [Flag]
Non rule 10b51 arr modified flag.
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax, Total
Total amounts included in AOCI, net of tax not yet recognized as components of net periodic expense
Public Utilities Amount of System Safety and Integrity Rider Moved to Base Rates and Termination of the System Safety and Integrity Rider
Public Utilities Amount of System Safety and Integrity Rider Moved to Base Rates and Termination of the System Safety and Integrity Rider
Public utilities amount of system safety and integrity rider moved to base rates and termination of the system safety and integrity rider.
Distribution
Public Utilities, Property, Plant and Equipment, Distribution
NorthWestern.
NorthWestern
NorthWestern [Member]
Income tax receivable, net
Income Taxes Receivable, Current
Other financing activities
Proceeds from (Payment for) Other Financing Activity
Other financing activities
KANSAS
Kansas
Intangible assets, net
Intangible assets, net, beginning balance
Intangible assets, net, ending balance
Intangible Assets, Net (Excluding Goodwill)
Intangible Assets, Net (Excluding Goodwill), Total
Line of Credit Facility [Line Items]
Accrued property taxes
Accrual for Taxes Other than Income Taxes, Current
AFUDC Equity
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity
Derivatives, Fair Value [Line Items]
Energy Related Inventory, Natural Gas in Storage
Natural gas in storage
Revisions to Prior Estimates
Asset Retirement Obligation, Revision of Estimate
Assets [Abstract]
ASSETS
Public utilities, number of former riders replaced with a new comprehensive safety and integrity rider.
Public Utilities Number Of Former Riders Replaced With A New Comprehensive Safety And Integrity Rider
Derivative Liabilities, Current [Member]
Line item in the statement of financial position in a classified presentation in which the fair value amounts of the derivative instruments are included.
Derivative liabilities, current
Risk-free rate
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Risk Free Interest Rate
Deferred financing cost amortization
Amortization of Debt Issuance Costs and Discounts
Amortization of Debt Issuance Costs and Discounts, Total
Other revenues
Other [Member]
Other [Member]
Netting Contract by Category [Axis]
Netting Contract, Category [Axis]
Netting Contract by Category [Axis]
Document Fiscal Year Focus
Document Fiscal Year Focus
Schedule of Accumulated Other Comprehensive Income (Loss)
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]
Valuation Allowance, Operating Loss Carryforwards
SEC Schedule, 12-09, Valuation Allowance, Operating Loss Carryforward [Member]
Senior Unsecured Notes Due 2046
Senior Unsecured Notes Due 2046 [Member]
Senior Unsecured Notes Due 2046 [Member]
Settlement Agreement For A General Rate Increase [Member]
Settlement agreement for a general rate increase.
Received Final Approval for a Settlement Agreement for a General Rate Increase
Investing activities:
Cash Provided by (Used in) Investing Activity, Including Discontinued Operation [Abstract]
Retirement Benefits [Abstract]
Accounts payable
Accounts Payable, Current
Accounts Payable, Current, Total
Lessor, Operating Lease, Payment to be Received, Year One
2026
Components of Net Periodic Benefit Cost
Schedule of Net Benefit Costs [Table Text Block]
Plan participants’ contributions
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant
Utilities Group
Utilities Group [Member]
Utilities Group - consists of our Electric Utilities and our Gas Utilities segments
Federal
Deferred Federal Income Tax Expense (Benefit)
Schedule of Changes in Fair Value of Plan Assets
Schedule of Changes in Fair Value of Plan Assets [Table Text Block]
Share-based compensation
Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture
Shares Issued, Value, Share-Based Payment Arrangement, after Forfeiture, Total
Deferred taxes on flow through accounting
Flow Through Accounting [Member]
The income tax effects of certain tax items are reflected in cost of service for the customer in which the tax benefits are realized and result in lower utiity rates. The regulatory treatment under flow-through accounting was applied for this tax benefit generated by utility costs that were previously capitalized for tax purposes in a rate case settlement and resulted in a lower rate increase. A regulatory asset was established to reflect the future increase in taxes payable recovered from sutomers as the temporarty difference reverses.[Member]
Noncontrolling Interest
Consolidation, Subsidiaries or Other Investments, Consolidated Entities, Policy [Policy Text Block]
Transaction Type [Axis]
Transaction Type [Axis]
Position [Axis]
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Cost
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member]
Future Amortization Expense, Year One
Finite-Lived Intangible Asset, Expected Amortization, Year One
Regulatory assets
Increase (Decrease) in Other Regulatory Assets
Regulatory assets
Regulatory assets
Pending Litigation [Member]
Pending Litigation
South Dakota Electric
Black Hills Energy - South Dakota Electric
South Dakota Electric [Member]
South Dakota Electric
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits [Roll Forward]
Public Utilities, Approved Rate Increase (Decrease), Amount
Public Utilities, Approved Rate Increase (Decrease), Amount
Rate of increase in compensation levels
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase
Fair Value Disclosures [Abstract]
Fair Value Disclosures [Abstract]
Power Generation
Power Generation [Member]
Power Generation
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies Disclosure [Abstract]
Transportation, Storage, Gathering And Coal Agreements [Member]
Natural gas supply, transportation and storage agreements
Natural Gas Supply, Transportation and Storage Agreements [Member]
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets
Defined Benefit Plan, Alternative Investments, Fair Value Of Plan Assets
Electric transmission
Electric Transmission [Member]
Gas price derivatives
Price Risk Derivative [Member]
Debt Instrument [Axis]
Debt Instrument [Axis]
Plant Net of Accumulated Depreciation
Jointly Owned Utility Plant, Net Ownership Amount
Plant Net of Accumulated Depreciation
Derivative Instrument [Axis]
Derivative Instrument [Axis]
Derivative Instrument [Axis]
Interest cost
Defined Benefit Plan, Interest Cost
Share-Based Payment Arrangement [Abstract]
Unrecognized compensation expense
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total
Derivative Assets, Total
Assets, Fair Value Disclosure
Assets, Fair Value Disclosure, Total
Sale of Stock [Axis]
Sale of Stock [Axis]
Construction Work in Progress
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress
Derivatives and Hedging Activities
Derivatives, Policy [Policy Text Block]
Defined Benefit Plan, Expected Future Benefit Payment, Year One
2026
Defined Benefit Plan, Fair Value of Plan Assets, Excluding Net Asset Value investments
Defined Benefit Plan, Fair Value of Plan Assets, Excluding Net Asset Value investments
Defined Benefit Plan, Fair Value of Plan Assets, Excluding Net Asset Value investments
Revenue
Revenues
Revenues, Total
Net cash (used in) investing activities
Cash Provided by (Used in) Investing Activity, Including Discontinued Operation
Contingencies And Environmental Liabilities [Policy Text Block]
Contingencies and environmental liabilities.
Contingencies and Environmental Liabilities
Title of 12(b) Security
Title of 12(b) Security
Schedule of Segment Reporting Information, by Segment [Table]
Schedule of Segment Reporting Information, by Segment [Table]
Line of Credit Facility, Interest Rate at Period End
Line of Credit Facility, Interest Rate at Period End
Weighted average interest rates
Deferred tax liabilities:
Deferred Tax Liabilities, Net [Abstract]
Risk Management And Derivatives
Derivative Instruments and Hedging Activities Disclosure [Text Block]
Forfeited (usd per share)
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value
Related Party [Domain]
Related and Nonrelated Parties [Domain]
Thereafter
Long-Term Debt, Maturity, after Year Five
Income Taxes
Income Tax Disclosure [Text Block]
IUC Approval for General Rate Increase [Member]
IUC approval for general rate increase.
IUC Approval for General Rate Increase
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset
Derivative Asset, Subject to Master Netting Arrangement, Gross Liability and Collateral, Obligation to Return Cash, Offset
Derivative Asset, Fair Value, Gross Liability and Obligation to Return Cash, Offset, Total
Reductions in valuation allowance
Tax Credit Carryforward, Valuation Allowance reduced
Tax dredit carryforward, valuation allowance reduced.
Interest Expense
Interest Expense [Member]
Percentage Of Partial Redemptions Subject To Redemption Gate
Percentage of partial redemptions subject to redemption gate.
Percentage of partial redemptions subject to redemption gate
Remediation Cost
Remediation cost
Site remediation cost
Lessor, Operating Lease, Payments to be Received
Lessor, Operating Lease, Payment to be Received
Total lease receivables
Other deferred credits and other liabilities
Other Liabilities, Noncurrent
Consolidated Entities [Axis]
Consolidated Entities [Axis]
Retail - Electric , Natural Gas and Coal [Member]
Retail - Electric , Natural Gas and Coal
Retail - Electric , Natural Gas and Coal
Total deferred credits and other liabilities
Liabilities, Other than Long-Term Debt, Noncurrent
Legal Entity [Axis]
Legal Entity [Axis]
Change in certain operating assets and liabilities:
Adjustment to Reconcile Net Income to Cash Provided by (Used in) Operating Activity, Increase (Decrease) in Operating Capital [Abstract]
Settlement Agreement Reached with the CPUC Staff and Various Intervenors for a General Rate Increase which is Subject to CPUC Approval
Settlement Agreement Reached with the CPUC Staff and Various Intervenors for a General Rate Increase which is Subject to CPUC Approval [Member]
Settlement agreement reached with the CPUC staff and various intervenors for a general rate increase which is subject to CPUC approval member.
Schedule of Net Periodic Benefit Cost Not yet Recognized
Schedule of Net Periodic Benefit Cost Not yet Recognized [Table Text Block]
Property, Plant and Equipment
Property, Plant and Equipment [Table Text Block]
Letters of Credit Outstanding, Amount
Letters of Credit Outstanding, Amount
Letters of credit
Transmission
Transmission [Member]
Transmission.
Fair value of plan assets at end of year
Fair value of plan assets at beginning of year
Defined Benefit Plan, Plan Assets, Amount
Defined Benefit Plan, Plan Assets, Amount
Income Tax Disclosure [Abstract]
Income Tax Disclosure [Abstract]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Table]
Fair Value, Recurring and Nonrecurring [Table]
Public Utilities, Term Extension of System Safety and Integrity Rider
Public Utilities, Term Extension of System Safety and Integrity Rider
Public Utilities, Term Extension of System Safety and Integrity Rider
Summary of Operating Loss Carryforwards [Table Text Block]
Summary of Operating Loss and Tax Credit Carryforwards
Business Combination [Text Block]
Pending Merger with NorthWestern Energy
Lessor, Operating Lease, Payment to be Received, Year Four
2029
Additional Paid-in Capital
Additional Paid-in Capital [Member]
Business Acquisition Exchange Ratio On Common Stock
Business acquisition exchange ratio on common stock.
Business acquisition exchange ratio on common stock
Measurement Frequency [Domain]
Measurement Frequency [Domain]
Income Statement Location [Axis]
Statement of Income Location, Balance [Axis]
Trading Symbol
Trading Symbol
Schedule of Finite-Lived Intangible Assets [Table]
Intangible Asset, Finite-Lived [Table]
Property, Plant and Equipment
Property, Plant and Equipment Disclosure [Text Block]
Senior Unsecured Notes Due 2027
Senior Unsecured Notes Due 2027 [Member]
Senior Unsecured Notes Due 2027 [Member]
Tax Year Subject to Examination
Open Tax Year
Deferred energy and gas costs
Deferred energy and fuel cost adjustments
Deferred Fuel Costs [Member]
Business Group [Axis]
Business Group [Axis]
Business Group (grouping of segments) [Axis]
Gain on Business Interruption Insurance Recovery, Statement of Income or Comprehensive Income [Extensible Enumeration]
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent, Total
Nontaxable or Nondeductible Items, percent
Public utilities, requested debt capital structure, percentage
Public Utilities, Requested Debt Capital Structure, Percentage
Subsequent Event Type [Axis]
Subsequent Event Type [Axis]
Lessor, Operating Lease, Payment to be Received, Year Five
2030
Intangible Assets
Schedule of Finite-Lived Intangible Assets [Table Text Block]
Accrued employee compensation, benefits and withholdings
Employee-related Liabilities, Current
Employee-related Liabilities, Current, Total
Financing activities:
Cash Provided by (Used in) Financing Activity, Including Discontinued Operation [Abstract]
Available borrowing capacity.
Available Borrowing Capacity
Available capacity
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage
Service cost effective discount rate
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate Service Cost
Defined benefit plan assumptions used calculating benefit obligation discount rate service cost.
Fair Value, Measurements, Recurring
Fair Value, Recurring [Member]
Carrying Costs
Carrying Costs [Member]
Carrying Costs
Derivative Instruments Gain Losses Reclassified From Accumulated OCI Into Income Effective Portion Net
Derivative instruments gain losses reclassified from accumulated OCI into income effective portion net.
A P S C Aauthorized.
A P S C Authorized Member
Settlement agreement reached with APSC Staff and various intervenors
Equity Components [Axis]
Equity Components [Axis]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Total other income (expense)
Nonoperating Income (Expense)
Income Tax Disclosure [Table]
Income tax disclosure.
Equity Component [Domain]
Equity Component [Domain]
Asset Class [Axis]
Derivative Assets, Current [Member]
Line item in the statement of financial position in a classified presentation in which the fair value amounts of the derivative instruments are included.
Derivative assets, current
Lessor, Lease, Description [Line Items]
Lessor, Lease, Description [Line Items]
State and Local Tax Jurisdiction, Other [Member]
Other
Liability for Uncertain Tax Positions, Noncurrent, Period Start
Liability for Uncertain Tax Positions, Noncurrent, Period End
Liability for Uncertainty in Income Taxes, Noncurrent
Electric distribution
Electric Distribution [Member]
Interest expense incurred net of amounts capitalized
Interest expense
Interest Costs Incurred
Interest Costs Incurred, Total
Investments
Investments, Total
Investments
GT Resources, LLC
GT Resources, LLC [Member]
GT Resources, LLC v. Black Hills Corporation, Case No. 2020CV30751 (U.S. District Court for the City and County of Denver, Colorado)
Document Annual Report
Document Annual Report
Business Combination [Axis]
First Mortgage Bonds Due 2032
First Mortgage Bonds Due 2032 [Member]
First Mortgage Bonds Due 2032 [Member]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase
Rate of increase in compensation levels
Black Hills Energy - Colorado Gas
Black Hills Energy, Colorado Gas [Member]
Black Hills Energy, Colorado Gas [Member]
Customer [Axis]
Customer [Axis]
Senior Unsecured Notes Due 2030
Senior Unsecured Notes Due 2030 [Member]
Senior Unsecured Notes Due 2030
Senior Unsecured Notes Due 2031 [Member]
Senior unsecured notes due 2031.
Senior Unsecured Notes Due 2031
Depreciation, Depletion and Amortization, Nonproduction
Depreciation, Depletion and Amortization, Nonproduction, Total
Depreciation and amortization
Error Correction, Type [Domain]
Error Correction, Type [Domain]
Percentage Of Monthly Redemption
Percentage Of Monthly Redemption
Percentage of shares that may be redeemed at the end of each month.
Statement of Comprehensive Income [Abstract]
Statement of Comprehensive Income [Abstract]
Public Utilities - Length of Electric Transmission Lines to Receive Infrastructure Investments
Public Utilities - Length of Electric Transmission Lines to Receive Infrastructure Investments
Public Utilities - Length of Electric Transmission Lines to Receive Infrastructure Investments
Deferred Energy and Gas Costs Member
Deferred energy and gas costs
Deferred energy and gas costs.
Public Utilities, Property, Plant and Equipment, Construction Work in Progress
Construction work-in-progress
Post-65 for next year - All Plans
Defined Benefit Plan, Health Care Cost Trend Rate Assumed, Next Fiscal Year
Maximum
Maximum [Member]
Derivative Liabilities, Total
Liabilities, Fair Value Disclosure
Liabilities, Fair Value Disclosure, Total
Designated as Hedging Instrument
Designated as Hedging Instrument [Member]
Statistical Measurement [Axis]
Statistical Measurement [Axis]
Accounts payable and other current liabilities
Increase (Decrease) in Other Accounts Payable and Accrued Liabilities
Common Stock, Value, Issued
Common stock $1.00 par value; 100,000,000 shares authorized; issued: 75,520,234 and 71,676,756, respectively
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Insurance Settlements Receivable, Noncurrent
Insurance Settlements Receivable, Noncurrent
Litigation Status [Domain]
Deferred gas cost adjustments
Deferred Gas Cost Adjustments [Member]
Deferred gas cost adjustments.
Reclassification out of Accumulated Other Comprehensive Income
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]
Netting Contract by Category [Domain]
Netting Contract, Category [Domain]
[Domain] for Netting Contract by Category [Axis]
Principles of Consolidation
Consolidation, Policy [Policy Text Block]
Total equity
Beginning balance
Ending balance
Equity, Including Portion Attributable to Noncontrolling Interest
Thereafter
Lessor, Operating Lease, Payment to be Received, after Year Five
Interest cost effective discount rate
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate Interest Cost
Defined benefit plan assumptions used calculating benefit obligation discount rate interest cost.
Jointly Owned Facilities
Jointly Owned Facilities, Utility and Non-Regulated [Text Block]
Disclosure of proportionate interests in jointly owned facilities (regulated utiliyt and non-regulated). Includes the amount of plants in service, the accumulated depreciation (if available), the amount of construction in progress, and the proportionate share. Includes statements that the amounts represent the company's share in each joint facility and that it must provide its own financing. States that the company's share of direct expenses of the joint facilities is included in the corresponding operating expenses on its income statement (for example, fuel, maintenance, other operating expense). [Text Block]
Deferred Tax Assets, Operating Loss Carryforwards
Deferred Tax Assets, Operating Loss Carryforwards, Total
Federal NOL
Cybersecurity Risk Management Processes for Assessing, Identifying, and Managing Threats [Text Block]
Accounts receivable and other current assets
Increase (Decrease) in Accounts Receivable and Other Operating Assets
Integrated Generation
Integrated Generation [Member]
Integrated Generation
Income Tax Reconciliation Regulatory Other Percentage
Income tax reconciliation regulatory other percentage.
Other, percent
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent
State and local income taxes, net of federal income tax effect, percent
Net borrowings (payments) of Revolving Credit Facility and CP Program
Net (payments) borrowings of Revolving Credit Facility and Commercial Paper Program
Net (payments) borrowings of Revolving Credit Facility and Commercial Paper Program
Supply Commitment [Axis]
Supply Commitment [Axis]
Entity Public Float
Entity Public Float
Black Hills Corporation’s common stock volatility
Share-Based Compensation Arrangement by Share-Based Payment Award, Fair Value Assumptions, Expected Volatility Rate
Preferred Stock, Shares Authorized
Preferred Stock, Shares Authorized
Accrued interest
Interest Payable, Current
Lessor - lease term
Lessor, Operating Lease, Term of Contract
Customer deposits and prepayments
Customer Deposits and Prepayments
Accrued Liabilities - Customer Deposits and Prepayments
Number of Defined Pension Plans
Number of Defined Pension Plans
Number of Defined Pension Plans
Revenue from Contract with Customer [Text Block]
Revenue
Business Combination [Table]
Entity Registrant Name
Entity Registrant Name
Unrecognized Tax Benefits, Interest Accrued
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Total
Financing
Debt Disclosure [Text Block]
Environmental Remediation Site [Domain]
Environmental Remediation Site [Domain]
Long-term Contract for Purchase of Electric Power [Axis]
Long-Term Contract for Purchase of Electric Power [Axis]
Future [Member]
Natural gas futures purchased
Entity Voluntary Filers
Entity Voluntary Filers
Future Amortization Expense, Year Two
Finite-Lived Intangible Asset, Expected Amortization, Year Two
Other income (expense), net
Other Nonoperating Income (Expense)
Other Nonoperating Income (Expense), Total
Additional paid-in capital
Additional Paid in Capital
Additional Paid in Capital, Total
Accumulated Other Comprehensive Income (Loss) [Table]
Accumulated Other Comprehensive Income (Loss) [Table]
Deferred State and Local Income Tax Expense (Benefit)
State
Subsequent Events [Abstract]
Business Group [Domain]
Business Group [Domain]
[Domain] for Business Group (grouping of segments) [Axis]
Consolidated Entities [Domain]
Consolidated Entities [Domain]
Future Amortization Expense, Year Three
Finite-Lived Intangible Asset, Expected Amortization, Year Three
Income tax (expense)
Income Tax Expense (Benefit)
Income Tax Expense (Benefit)
Income tax (expense)
Effective Tax Rate
Income tax benefit (expense)
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage
Measurement Frequency [Axis]
Measurement Frequency [Axis]
Dividends on common stock (usd per share)
Common Stock, Dividends, Per Share, Cash Paid
Defined Benefit Plan, Expected Future Benefit Payment, Year Five
2030
Common stock issued
Proceeds from Issuance of Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Entity Common Stock, Shares Outstanding
Entity Common Stock, Shares Outstanding
Share-Based Compensation
Compensation Related Costs, Policy [Policy Text Block]
Accumulated other comprehensive income (loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period Start
Accumulated Other Comprehensive Income (Loss), Net of Tax, Period End
Accumulated Other Comprehensive Income (Loss), Net of Tax
Accumulated Other Comprehensive Income (Loss), Net of Tax, Total
Consolidation Items [Axis]
Consolidation Items [Axis]
Write-offs and Other Deductions
Accounts Receivable, Allowance for Credit Loss, Writeoff
Winter Storm Uri
Winter Storm Uri [Member]
Winter Storm Uri
Property, plant and equipment additions
Payments to Acquire Property, Plant, and Equipment
Payments to Acquire Property, Plant, and Equipment, Total
Other investing activities
Payment for (Proceeds from) Other Investing Activity
Other investing activities
Performance Shares, Granted in Period
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position [Abstract]
Amounts recognized on our Consolidated Balance Sheets as of December 31:
State tax credits
Deferred Tax Assets, Tax Credit Carryforwards, Other
Total Assets
TOTAL ASSETS
Assets
Interest expense incurred net of amounts capitalized (including amortization of debt issuance costs, premiums and discounts)
Interest expense incurred net of amounts capitalized (including amortization of debt issuance costs, premiums and discounts) [Member]
Interest expense incurred net of amounts capitalized (including amortization of debt issuance costs, premiums and discounts)
Materials, Supplies and Fuel
Inventory, Policy [Policy Text Block]
Property, Plant and Equipment [Table]
Property, Plant and Equipment [Table]
Total State
Income Tax Paid, State and Local, after Refund Received
Income Statement [Abstract]
Income Statement [Abstract]
Ratio of Indebtedness to Net Capital
Consolidated indebtedness to capitalization ratio
Defined Contribution Plan
Retirement Plan Name [Domain]
Non-controlling interest
Noncontrolling Interest in Variable Interest Entity
Pueblo Airport Generation
Pueblo Airport Generation [Member]
Jointly Owned Pueblo Airport Generating Facility [Member]
Fair Value Measurements
Fair Value of Financial Instruments, Policy [Policy Text Block]
Reductions for prior year tax positions
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions
Recognized net actuarial loss (gain)
Defined Benefit Plan, Amortization of Gain (Loss)
Operating Loss Carryforwards, With no Expiration Date
Operating Loss Carryforwards, With no Expiration Date
Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws. Operating Loss Carryforwards, With no Expiration Date
Senior Unsecured Notes Due 2024
Senior Unsecured Notes Due 2024 [Member]
Senior Unsecured Notes Due 2024
Senior Unsecured Notes Due 2024 [Member]
Deferred income tax expense
Deferred income taxes
Deferred Income Tax Expense (Benefit)
Deferred income tax (expense)
Weighted Average
Weighted Average [Member]
Wyodak Plant
Wyodak Plant [Member]
Wyodak Plant - power generation plant owned 20% by Black Hills Power and 80% by Pacificorp[Member]
Issuance of common stock (in shares)
Stock Issued During Period, Shares, New Issues
Shares Vested
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Vested in Period
Performance Shares, Vested in Period
Schedule of Allocation of Plan Assets
Schedule of Allocation of Plan Assets [Table Text Block]
Variable Interest Entities
Consolidation, Variable Interest Entity, Policy [Policy Text Block]
Interest cost effective discount rate
Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate Interest Cost
Defined benefit plan assumptions used calculating net periodic benefit cost discount rate interest cost.
Cushion gas - depreciable
Cushion Gas - Depreciable [Member]
Cushion Gas - Depreciable [Member]
Earnings per share, Diluted (usd per share)
Earnings Per Share, Diluted
Earnings Per Share, Diluted, Total
Net income available for common stock, per share - Diluted
Segment information included in Consolidated Statements of Income
Schedule of Segment Reporting Information, by Segment [Table Text Block]
Position [Domain]
Operating Segments
Operating Segments [Member]
Long-term Purchase Commitment [Table]
Long-Term Purchase Commitment [Table]
Future Amortization Expense, Year Five
Finite-Lived Intangible Asset, Expected Amortization, Year Five
City Area Code
City Area Code
Net liability (asset) recognized
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position
Defined Benefit Plan, Amounts for Asset (Liability) Recognized in Statement of Financial Position, Total
Other comprehensive income (loss), net of tax
Other Comprehensive Income (Loss), Net of Tax
Other comprehensive income, net of tax
Error Correction, Other
Error Correction, Other [Member]
Auditor Name
Auditor Name
Black Hills Corporation
Black Hills Corporation [Member]
Black Hills Corporation [Member]
Percentage Of Full Redemptions Subject To Holdback Of Net Asset Value
Percentage of full redemptions subject to holdback of net asset value.
Percentage of full redemptions subject to holdback of net asset value
Finite-Lived Intangible Assets [Roll Forward]
Finite-Lived Intangible Assets [Roll Forward]
Total long-term debt
Long Term Debt Before The Deduction Of Deferred Financing Costs
Amount of long term debt before the deduction of deferred financing costs, but after the deduction of unamortized (discount) premium and includes current maturities.
Line of Credit Facility, Maximum Borrowing Capacity
Line of Credit Facility, Maximum Borrowing Capacity
Maximum amount outstanding (based on daily outstanding balances)
Business Combination [Line Items]
Unusual or Infrequent Item, or Both [Axis]
Unusual or Infrequent Item, or Both [Axis]
Term Loan - borrowings
Proceeds from Other Short-Term Debt
Operating Loss Carryforwards Valuation Allowance reduced
Operating loss carryforwards valuation allowance reduced.
Reductions in valuation allowance
Schedule of Defined Benefit Plans Disclosures [Table]
Defined Benefit Plan [Table]
Deferred Tax Assets, Tax Credit Carryforwards
Deferred Tax Assets, Tax Credit Carryforwards, Total
Credit Carryovers (net of discount)
Other comprehensive income (loss), cash flow hedge, gain (loss), reclassification, after tax
Reclassification of net realized (gains) losses on settled commodity derivatives (net of tax of $(0.7), $0.7, and $0.5, respectively)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax
August 4, 2020 ATM Program
August Four Twenty Twenty ATM Program [Member]
August 4, 2020 ATM program.
Trend Year
Defined Benefit Plan, Year Health Care Cost Trend Rate Reaches Ultimate Trend Rate
Purchase Power Contract, MEAN
Purchase Power Contract, MEAN, for up to 20 Megawatts
Purchase Power Contract, MEAN [Member]
Long-term Purchase Power Contract with MEAN
Litigation Case [Axis]
Summary of State Tax Carryforwards
Summary of Tax Credit Carryforwards [Table Text Block]
Segment Reporting Information
Segment Reporting Information [Line Items]
Segment Reporting Information [Line Items]
Industrial Development Revenue Bonds Due 2021
Industrial Development Revenue Bonds Due 2021 [Member]
Industrial Development Revenue Bonds Due 2021 [Member]
Number of Days Following the End of the Quarter When Distributions of Net Income Attributable to this Non-controlling Interest are Due
Number of Days Following the End of the Quarter When Distributions of Net Income Attributable to this Non-controlling Interest are Due
Number of Days Following the End of the Quarter When Distributions of Net Income Attributable to this Non-controlling Interest are Due
Excess deferred income taxes
Deferred Income Tax Amortization [Member]
Rate Action of a regulator resulting in return of prior period income tax over collections
Effective Income Tax Rate Reconciliation, Tax Credit, Other, Percent
Other, percent
Other, percent
Retirement Plan Name [Axis]
Retirement Plan Name [Axis]
Derivative Liability, Fair Value, Gross Liability
Derivative Liability, Fair Value, Gross Liability
Derivative Liability, Subject to Master Netting Arrangement, before Offset
Property, Plant and Equipment
Property Plant Equipment Excluding Construction In Progress
Property Plant Equipment excluding Construction in Progress
Letter of Credit
Letter of Credit [Member]
Variable interest rate (percent)
Long-Term Debt, Percentage Bearing Variable Interest, Percentage Rate
Derivative liabilities, current
Derivative Liability, Current
Property, plant and equipment
Total property, plant and equipment, net
Property, Plant and Equipment, Net
Property, plant and equipment, net
Defined Benefit Plan, Expected Future Benefit Payment, Year Three
2028
Regulatory liabilities, non-current
Regulatory Liability, Noncurrent
Public Utilities Term of Power Purchase Agreement
Public Utilities Term of Power Purchase Agreement
Public Utilities Term of Power Purchase Agreement
Operating income
Operating Income (Loss)
Operating income (loss)
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate
Pension benefit obligation effective discount rate
Retained Earnings
Retained Earnings [Member]
Term Loan - repayments
Repayments of Other Short-term Debt
Repayments of Other Short-Term Debt
Transaction [Domain]
Transaction [Domain]
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss)
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member]
Approval from IUC for A Settlement Agreement For A General Rate Increase [Member]
Approval from IUC for a settlement agreement for a general rate increase.
Received Final Approval from the IUC for a Settlement Agreement for a General Rate Increase
Wyoming Public Service Commission
Wyoming Public Service Commission [Member]
Wyoming Public Service Commission
Stock compensation
Share-Based Payment Arrangement, Noncash Expense
Share-Based Payment Arrangement, Noncash Expense, Total
Payments of Stock Issuance Costs
Payments of Stock Issuance Costs
Fixed for Float Swaps Purchased [Member]
Fixed for Float Swaps Purchased [Member]
Natural gas over-the-counter swaps, net
Schedule of Guarantor Obligations [Table]
Guarantor Obligation [Table]
Non-cash Revision to Capitalized Asset Retirement Costs
The amount of non-cash revision to property, plant and equipment for capitalized asset retirement costs
Increase (decrease) in capitalized assets associated with asset retirement obligations
Unrecorded Unconditional Purchase Obligation, to be Paid, Year Four
2029
Unrecorded Unconditional Purchase Obligation
Total future commitments
(Tax) benefit on reclassification adjustment of benefit plan liability - prior service cost
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, Tax
Fair Value, Inputs, Level 1
Fair Value, Inputs, Level 1
Fair Value, Inputs, Level 1 [Member]
Power purchased
Power Purchased [Member]
Power Purchased [Member]
Class of Stock [Line Items]
Class of Stock [Line Items]
Net cash provided by (used in) financing activities
Cash Provided by (Used in) Financing Activity, Including Discontinued Operation
Short-Term Debt [Line Items]
Short-Term Debt [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period
Employee Benefit Plans And Related Deferred Taxes Assets [Member]
Employee Benefit Plans And Related Deferred Taxes Assets [Member]
Employee benefit plans and related deferred taxes
Lessor, Operating Lease, Payment to be Received, Year Three
2028
WPSC Approved a Settlement Agreement for a General Rate Increase and is Expected to Issue a Final Written Order
WPSC Approved a Settlement Agreement for a General Rate Increase and is Expected to Issue a Final Written Order [Member]
WPSC approved a settlement agreement for a general rate increase and is expected to issue a final written order member.
Effective Income Tax Rate Reconciliation, Nondeductible Expense, Percent [Abstract]
Nontaxable or Nondeductible Items
Auditor Location
Auditor Location
Deferred Income Tax Liabilities, Net
Deferred income tax liabilities, net
Other income (expense):
Nonoperating Income (Expense) [Abstract]
Derivative Contract [Domain]
Derivative Contract [Domain]
Derivative Contract [Domain]
Accrual for Environmental Loss Contingencies - Pueblo Airport Generation Site
Accrual for Environmental Loss Contingencies
Accrual for Environmental Loss Contingencies, Total
Accrual for Environmental Loss Contingencies, Beginning Balance
Accrual for Environmental Loss Contingencies, Ending Balance
Schedule of Goodwill [Table]
Goodwill [Table]
Derivative, Remaining Maturity
Derivative, Remaining Maturity
Antidilutive Securities
Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]
Income Tax Authority [Domain]
Income Tax Jurisdiction [Domain]
Entity Interactive Data Current
Entity Interactive Data Current
Defined Benefit Plan, Plan Assets, Category [Axis]
Defined Benefit Plan, Plan Assets, Category [Axis]
Income Statement Location [Domain]
Statement of Income Location, Balance [Domain]
Fair Value Measurement [Domain]
Fair Value Measurement [Domain]
Operating activities:
Cash Provided by (Used in) Operating Activity, Including Discontinued Operation [Abstract]
Manufactured Gas Plant
Manufactured Gas Plant [Member]
Manufactured Gas Plant [Member]
Services transferred over time
Transferred over Time [Member]
Gas transmission
Gas Transmission Equipment [Member]
Cost of removal
Removal Costs [Member]
Effective Income Tax Reconciliation, Amortization Of Excess Deferred Income Tax Expense
Effective Income Tax Reconciliation, Amortization Of Excess Deferred Income Tax Expense
Amortization of excess deferred income taxes, percent
Income Tax Paid, State and Local, after Refund Received [Abstract]
State:
Unbilled Receivables, Current
Unbilled Revenue
Schedule of Employer Contribution to Employee Benefit Plans
Schedule of Employer Contribution to Employee Benefit Plans [Table Text Block]
Schedule of Employer Contribution to Defined Benefit and Defined Contribution Plans [Table Text Block]
Cumulative Effect, Period of Adoption [Domain]
Cumulative Effect, Period of Adoption [Domain]
Line of Credit Facility, Current Borrowing Capacity
Line of Credit Facility, Current Borrowing Capacity
Entity Tax Identification Number
Entity Tax Identification Number
Restricted Net Assets for Subsidiaries
Amount of Restricted Net Assets for Consolidated and Unconsolidated Subsidiaries
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Equity, Including Portion Attributable to Noncontrolling Interest [Abstract]
Revenue:
Revenues [Abstract]
Regulated Operation, Regulatory Asset [Table]
Long-Term Debt, Type [Axis]
Employee benefit plans
Pension and Other Postretirement Benefits Cost (Reversal of Cost)
Pension and Other Postretirement Benefits Cost (Reversal of Cost), Total
Debt Instrument, Term
Debt Instrument, Term
Common Collective Trust Funds [Member]
Common collective trust funds.
Common Collective Trust Funds
Colorado Electric and Black Hills Colorado IPP
Colorado Electric and Black Hills Colorado IPP [Member]
Colorado Electric and Black Hills Colorado IPP
Construction in Progress, Gross
Construction work-in-progress, gross
Local Phone Number
Local Phone Number
Related Party Transaction [Domain]
Related Party Transaction [Domain]
Segment Reporting Information, Additional Information [Abstract]
Segment Reporting Information, Additional Information [Abstract]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net periodic benefit expense
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax
Reclassification adjustment of benefit plan liability - net loss (net of tax of $0.2, $(0.1), and $0, respectively)
Reclassification adjustment of benefit plan liability - net loss (net of tax of $0.2, $(0.1), and $0, respectively)
Auditor Opinion [Text Block]
Long [Member]
Long
Issuance costs
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs
Financing Receivable, Current, Allowance for Credit Loss
Financing Receivable, Current, Allowance for Credit Loss [Table Text Block]
Production, processing and storage
Public Utilities, Property, Plant and Equipment, Generation or Processing
Derivative Asset Statement Of Financial Position Extensible Enumeration Not Disclosed Flag
Derivative asset statement of financial position extensible enumeration not disclosed flag.
Derivative Assets, Fair Value Disclosure
Other comprehensive income (loss), before reclassifications
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers
Revenue from Contract with Customer, Excluding Assessed Tax
Total guarantees
Guarantor Obligations, Maximum Exposure, Undiscounted
Public Utilities, Requested Rate Increase (Decrease), Amount
Public Utilities, Requested Rate Increase (Decrease), Amount
Inventory, Net [Abstract]
Inventory, Net [Abstract]
Cash
Cash and Cash Equivalents [Member]
Cash and Cash Equivalents
Commercial Paper
Commercial Paper [Member]
Shares available for grant
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant
Weighted-average recognition period
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent
Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent
Income Tax Paid, Federal, after Refund Received [Abstract]
Federal:
Schedule of Stock by Class [Table]
Stock, Class of Stock [Table]
Services transferred at a point in time
Transferred at Point in Time [Member]
Entity Emerging Growth Company
Entity Emerging Growth Company
Accrual for Environmental Loss Contingencies, Gross
Accrual for Environmental Loss Contingencies, Gross
Accrual for Environmental Loss Contingencies, Gross, Total
Black Hills Energy - Nebraska Gas
Black Hills Energy - Nebraska Gas [Member]
Black Hills Energy - Nebraska Gas [Member]