v3.26.1
Fair Value Measurements - Schedule of Net Asset Value Investments are Included to Permit Reconciliation to the Statement of Net Assets Available for Benefits (Details) - EBP 002 - USD ($)
Dec. 31, 2025
Dec. 31, 2024
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments $ 1,696,168,778 $ 1,621,592,006
Fair Value Hierarchy    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 1,432,424,003 1,382,882,328
Fair Value Hierarchy | Berkshire B ESOP Fund - Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 615,234,016 615,066,467
Fair Value Hierarchy | Berkshire B Unitized Stock Fund - Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 91,803,493 93,892,872
Fair Value Hierarchy | Berkshire B Unitized Stock Fund - Money Market    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 1,196,695 1,209,013
Fair Value Hierarchy | Mutual Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 724,189,799 672,713,976
Active Markets for Identical Assets (Level 1)    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 1,432,424,003 1,381,673,315
Active Markets for Identical Assets (Level 1) | Berkshire B ESOP Fund - Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 615,234,016 615,066,467
Active Markets for Identical Assets (Level 1) | Berkshire B Unitized Stock Fund - Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 91,803,493 93,892,872
Active Markets for Identical Assets (Level 1) | Berkshire B Unitized Stock Fund - Money Market    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 1,196,695 0
Active Markets for Identical Assets (Level 1) | Mutual Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 724,189,799 672,713,976
Other Observable Inputs (Level 2)    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 1,209,013
Other Observable Inputs (Level 2) | Berkshire B ESOP Fund - Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 0
Other Observable Inputs (Level 2) | Berkshire B Unitized Stock Fund - Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 0
Other Observable Inputs (Level 2) | Berkshire B Unitized Stock Fund - Money Market    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 1,209,013
Other Observable Inputs (Level 2) | Mutual Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 0
Significant Unobservable Inputs (Level 3)    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 0
Significant Unobservable Inputs (Level 3) | Berkshire B ESOP Fund - Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 0
Significant Unobservable Inputs (Level 3) | Berkshire B Unitized Stock Fund - Stock    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 0
Significant Unobservable Inputs (Level 3) | Berkshire B Unitized Stock Fund - Money Market    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 0
Significant Unobservable Inputs (Level 3) | Mutual Funds    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments 0 0
Net Asset Value Per Share | Collective Trust Fund    
EBP, Investment, Fair Value and NAV [Line Items]    
Total investments $ 263,744,775 $ 238,709,678