v3.26.1
Investment Partnerships - Schedule of Financial Information (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Mar. 31, 2026
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Schedule of Equity Method Investments [Line Items]              
Total assets $ 1,058,584       $ 1,058,584   $ 1,025,383
Total liabilities 514,796       514,796   501,954
Net earnings (loss) $ 39,926 $ (14,531) $ 50,931 $ (33,275) $ 25,395 $ 17,656  
Lion Fund              
Schedule of Equity Method Investments [Line Items]              
Biglari Holdings' ownership interest 92.80%   91.20%   92.80% 91.20%  
Lion Fund II              
Schedule of Equity Method Investments [Line Items]              
Biglari Holdings' ownership interest 91.70%   88.80%   91.70% 88.80%  
Lion Fund              
Schedule of Equity Method Investments [Line Items]              
Total assets $ 980,989       $ 980,989   750,172
Total liabilities 30,068       30,068   16,742
Total revenues         184,628 $ 58,537  
Net earnings (loss)         184,154 57,970  
Lion Fund II              
Schedule of Equity Method Investments [Line Items]              
Total assets 340,347       340,347   293,051
Total liabilities $ 180,513       180,513   $ 163,900
Total revenues         26,412 23,257  
Net earnings (loss)         $ 22,622 $ 18,396