v3.26.1
Derivatives (Effect of Commodity Derivative Instruments in Statements of Income) (Detail) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Derivative Instruments, Gain (Loss) [Line Items]    
Unrealized Gain (Loss) on Derivatives $ 318 $ 16
Commodity derivatives    
Derivative Instruments, Gain (Loss) [Line Items]    
Gain (Loss) (909) (65)
Commodity derivatives | Sales and other operating revenues    
Derivative Instruments, Gain (Loss) [Line Items]    
Gain (Loss) (62) 0
Unrealized Gain (Loss) on Derivatives (49) 0
Realized Gain (Loss), Investment and Derivative, Operating, before Tax (13) 0
Commodity derivatives | Cost of revenues    
Derivative Instruments, Gain (Loss) [Line Items]    
Gain (Loss) (840) (67)
Unrealized Gain (Loss) on Derivatives (440) (13)
Realized Gain (Loss), Investment and Derivative, Operating, before Tax (400) (54)
Commodity derivatives | Other income    
Derivative Instruments, Gain (Loss) [Line Items]    
Gain (Loss) (7) 2
Unrealized Gain (Loss) on Derivatives (30) (1)
Realized Gain (Loss), Investment and Derivative, Operating, before Tax $ 23 $ 3