v3.26.1
Schedule of Assets (Held at End of Year) - Schedule of Assets (Details) - EBP 002
12 Months Ended
Dec. 31, 2025
USD ($)
EBP, Schedule of Asset Held for Investment [Line Items]  
EBP, Plan Name EMPLOYEE SAVINGS AND STOCK OWNERSHIP PLAN OF GENERAL RE
Entity Tax Identification Number 06-1026471
EBP, Plan Number 002
Notes receivable from participants $ 3,925,283
Total assets held for investment purposes $ 1,700,094,061
Employee benefit plan, asset held for investment, participant loan, maturity year 2054
Investment, Identifier [Axis]: Collective Trust Fidelity Management Trust Co. Growth Company Commingled Pool A  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 251,877,448
EBP, Investment, Current Value, Type [Extensible Enumeration] Common Collective Trust [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity Management Trust Co [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Collective Trust Fidelity Management Trust Co. Managed Income Portfolio - Class 2  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 11,867,327
EBP, Investment, Current Value, Type [Extensible Enumeration] Common Collective Trust [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity Management Trust Co [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds American Beacon Large-Cap Fund R6  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 18,540,273
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] American Beacon [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
Investment, Identifier [Axis]: Mutual Funds American Funds Capital World Growth & Income Fund R6  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 17,223,341
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] American Funds [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
Investment, Identifier [Axis]: Mutual Funds BlackRock BlackRock Strategic Global Bond Fund K  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 7,652,946
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] BlackRock [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
Investment, Identifier [Axis]: Mutual Funds Fidelity Balanced Fund K  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 119,219,633
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Fidelity Emerging Markets K  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 16,277,242
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Fidelity Freedom Index 2010 IPR  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 153,815
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Fidelity Freedom Index 2015 IPR  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 3,117,545
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Fidelity Freedom Index 2020 IPR  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 10,317,147
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Fidelity Freedom Index 2025 IPR  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 27,048,541
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Fidelity Freedom Index 2030 IPR  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 25,015,807
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Fidelity Freedom Index 2035 IPR  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 23,190,872
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Fidelity Freedom Index 2040 IPR  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 29,216,288
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Fidelity Freedom Index 2050 IPR  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 12,376,158
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Fidelity Freedom Index 2060 IPR  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 642,775
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Fidelity Freedom Index Income IPR  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 1,417,119
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Fidelity Government Institutional Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 77,789,302
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Fidelity Overseas Fund K  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 17,167,641
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Fidelity Real Estate Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 7,270,371
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Fidelity S&P 500 Index  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 136,340,984
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Fidelity Spartan US Bond Index Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 32,983,363
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Fidelity [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Mutual Funds Neuberger Berman Genesis Trust Fund R6  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 16,287,488
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Neuberger Berman [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
Investment, Identifier [Axis]: Mutual Funds PIMCO High Yield Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 15,968,545
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] PIMCO [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
Investment, Identifier [Axis]: Mutual Funds Vanguard All World Index Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 20,251,400
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
Investment, Identifier [Axis]: Mutual Funds Vanguard Inflation Protected Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 13,101,104
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
Investment, Identifier [Axis]: Mutual Funds Vanguard Mid-Cap Index Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 43,487,760
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
Investment, Identifier [Axis]: Mutual Funds Vanguard Small-Cap Index Fund  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 32,132,339
EBP, Investment, Current Value, Type [Extensible Enumeration] Mutual Fund [Member]
EBP, Investment, Issuer Name [Extensible Enumeration] Vanguard [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
Investment, Identifier [Axis]: Separately Managed Funds Berkshire B Unitized Stock Fund - Money Market  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 1,196,695
EBP, Investment, Current Value, Type [Extensible Enumeration] us-gaap-ebp:EmployeeBenefitPlanPooledSeparateAccountMember
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
Investment, Identifier [Axis]: Separately Managed Funds Berkshire Hathaway Berkshire B Unitized Stock Fund - Common Stock  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 91,803,493
EBP, Investment, Current Value, Type [Extensible Enumeration] us-gaap-ebp:EmployeeBenefitPlanPooledSeparateAccountMember
EBP, Investment, Issuer Name [Extensible Enumeration] Berkshire Hathaway [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Investment, Identifier [Axis]: Separately Managed Funds Berkshire Hathaway Gen Re Berkshire B ESOP Fund - Common Stock  
EBP, Schedule of Asset Held for Investment [Line Items]  
Current Value $ 615,234,016
EBP, Investment, Current Value, Type [Extensible Enumeration] us-gaap-ebp:EmployeeBenefitPlanPooledSeparateAccountMember
EBP, Investment, Issuer Name [Extensible Enumeration] Berkshire Hathaway [Member]
EBP, Asset Held for Investment, Investment, Excluding Plan Interest in Master Trust, Participation Status [Extensible Enumeration] EBP, Participant-Directed [Member]
EBP, Asset Held for Investment, Party-in-Interest [true false] true
Minimum  
EBP, Schedule of Asset Held for Investment [Line Items]  
EBP, Asset Held for Investment, Participant Loan, Interest Rate 4.25%
Maximum  
EBP, Schedule of Asset Held for Investment [Line Items]  
EBP, Asset Held for Investment, Participant Loan, Interest Rate 10.50%