v3.25.4
Financing: Long-Term Debt (Details) - USD ($)
Dec. 31, 2025
Dec. 31, 2024
Debt Instrument [Line Items]    
Total long-term debt $ 4,735,000,000 $ 4,285,000,000
Less current maturities 0 0
Less unamortized deferred financing costs (26,100,000) (26,100,000)
Long-term debt, net of current maturities 4,701,100,000 4,250,200,000
Revolving Credit Facility    
Debt Instrument [Line Items]    
Less unamortized deferred financing costs (2,300,000) (2,400,000)
Black Hills Corporation    
Debt Instrument [Line Items]    
Long-term debt 4,200,000,000 3,750,000,000
Less unamortized debt discount $ (7,800,000) (8,700,000)
Black Hills Corporation | Senior Unsecured Notes Due 2026    
Debt Instrument [Line Items]    
Stated interest rate (percent) 3.95%  
Long-term debt $ 300,000,000 300,000,000
Black Hills Corporation | Senior Unsecured Notes Due 2027    
Debt Instrument [Line Items]    
Stated interest rate (percent) 3.15%  
Long-term debt $ 400,000,000 400,000,000
Black Hills Corporation | Senior Unsecured Notes Due 2028    
Debt Instrument [Line Items]    
Stated interest rate (percent) 5.95%  
Long-term debt $ 350,000,000 350,000,000
Black Hills Corporation | Senior Unsecured Notes Due 2029    
Debt Instrument [Line Items]    
Stated interest rate (percent) 3.05%  
Long-term debt $ 400,000,000 400,000,000
Black Hills Corporation | Senior Unsecured Notes Due 2030    
Debt Instrument [Line Items]    
Stated interest rate (percent) 2.50%  
Long-term debt $ 400,000,000 400,000,000
Black Hills Corporation | Senior Unsecured Notes Due 2031    
Debt Instrument [Line Items]    
Stated interest rate (percent) 4.55%  
Long-term debt $ 450,000,000 0
Black Hills Corporation | Senior Unsecured Notes Due 2033    
Debt Instrument [Line Items]    
Stated interest rate (percent) 4.35%  
Long-term debt $ 400,000,000 400,000,000
Black Hills Corporation | Senior Unsecured Notes Due 2034    
Debt Instrument [Line Items]    
Stated interest rate (percent) 6.15%  
Long-term debt $ 450,000,000 450,000,000
Black Hills Corporation | Senior Unsecured Notes Due 2035    
Debt Instrument [Line Items]    
Stated interest rate (percent) 6.00%  
Long-term debt $ 450,000,000 450,000,000
Black Hills Corporation | Senior Unsecured Notes Due 2046    
Debt Instrument [Line Items]    
Stated interest rate (percent) 4.20%  
Long-term debt $ 300,000,000 300,000,000
Black Hills Corporation | Senior Unsecured Notes Due 2049    
Debt Instrument [Line Items]    
Stated interest rate (percent) 3.88%  
Long-term debt $ 300,000,000 300,000,000
Black Hills Energy - South Dakota Electric | Electric Utilities    
Debt Instrument [Line Items]    
Long-term debt $ 340,000,000 340,000,000
Black Hills Energy - South Dakota Electric | Electric Utilities | First Mortgage Bonds Due 2032    
Debt Instrument [Line Items]    
Stated interest rate (percent) 7.23%  
Long-term debt $ 75,000,000 75,000,000
Black Hills Energy - South Dakota Electric | Electric Utilities | First Mortgage Bonds Due 2039    
Debt Instrument [Line Items]    
Stated interest rate (percent) 6.13%  
Long-term debt $ 180,000,000 180,000,000
Black Hills Energy - South Dakota Electric | Electric Utilities | First Mortgage Bonds Due 2044    
Debt Instrument [Line Items]    
Stated interest rate (percent) 4.43%  
Long-term debt $ 85,000,000 85,000,000
Wyoming Electric | Electric Utilities    
Debt Instrument [Line Items]    
Long-term debt 195,000,000 195,000,000
Wyoming Electric | Electric Utilities | Senior Unsecured Notes Due 2027    
Debt Instrument [Line Items]    
Long-term debt $ 10,000,000  
Wyoming Electric | Electric Utilities | First Mortgage Bonds Due 2044    
Debt Instrument [Line Items]    
Stated interest rate (percent) 4.53%  
Long-term debt $ 75,000,000 75,000,000
Wyoming Electric | Electric Utilities | Industrial Development Revenue Bonds Due 2027    
Debt Instrument [Line Items]    
Variable interest rate (percent) 3.35%  
Long-term debt $ 10,000,000 10,000,000
Wyoming Electric | Electric Utilities | First Mortgage Bonds Due 2037    
Debt Instrument [Line Items]    
Stated interest rate (percent) 6.67%  
Long-term debt $ 110,000,000 $ 110,000,000