v3.26.1
Related Party Transactions (Details) - USD ($)
$ in Millions
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
Related Party Transaction [Line Items]              
Distributions $ 1,300 $ 1,000 $ 1,500 $ 700 $ 2,300 $ 2,200  
Equity Method Investments and Joint Ventures [Abstract]              
Equity Method Investments Related to TTX $ 944       $ 944   $ 930
TTX Company              
Related Party Transaction [Line Items]              
Ownership Percentage in TTX Company 17.40%       17.40%    
TTX Company              
Related Party Transaction [Line Items]              
Car Hire Expenditures with TTX $ 112   $ 107   $ 215 213  
Parent Company              
Related Party Transaction [Line Items]              
Distributions         2,300 2,200  
Tax payments to Berkshire         692 699  
Tax refunds from Berkshire         0 $ 0  
Tax Payable, Berkshire $ 34       $ 34   $ 94