v3.26.1
Fair Value Measurements - Summary of Investments Measured at Fair Value on Recurring Basis (Details) - EBP 003 - USD ($)
Dec. 31, 2025
Dec. 31, 2024
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value $ 911,788,553 $ 789,443,230
Mutual Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value 296,914,418 265,983,973
Black Hills Corporation Common Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value 17,572,606 14,676,035
Self-Directed Brokerage Accounts - PCRA    
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value 39,467,717 36,331,870
Common Collective Trust Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value 557,833,812 472,451,352
Level 1    
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value 340,057,364 305,511,116
Level 1 | Mutual Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value 296,914,418 265,983,973
Level 1 | Black Hills Corporation Common Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value 17,572,606 14,676,035
Level 1 | Self-Directed Brokerage Accounts - PCRA    
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value 25,570,340 24,851,108
Level 2    
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value 13,897,377 11,480,762
Level 2 | Self-Directed Brokerage Accounts - PCRA    
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value 13,897,377 11,480,762
Fair Value, Inputs, Level 1, Level 2, and Level 3    
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value 353,954,741 316,991,878
Fair Value, Inputs, Level 1, Level 2, and Level 3 | Mutual Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value 296,914,418 265,983,973
Fair Value, Inputs, Level 1, Level 2, and Level 3 | Black Hills Corporation Common Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value 17,572,606 14,676,035
Fair Value, Inputs, Level 1, Level 2, and Level 3 | Self-Directed Brokerage Accounts - PCRA    
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value 39,467,717 36,331,870
Net Asset Value    
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value 557,833,812 472,451,352
Net Asset Value | Common Collective Trust Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Total Investments Measured at Fair Value $ 557,833,812 $ 472,451,352