v3.26.1
Property, Plant and Equipment, Net (Schedule of Property, Plant and Equipment) (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Cost $ 61,745 $ 71,431
Less: Accumulated depreciation, depletion and amortization (48,542) (57,187)
Property, plant and equipment, net 13,203 14,244
Operating Segments [Member] | USA Operations [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Cost 38,431 50,909
Less: Accumulated depreciation, depletion and amortization (30,471) (39,296)
Property, plant and equipment, net 7,960 11,613
Operating Segments [Member] | Canadian Operations [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Cost 22,502 19,690
Less: Accumulated depreciation, depletion and amortization (17,359) (17,168)
Property, plant and equipment, net 5,143 2,522
Corporate & Other [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, net 100 109
Proved Properties [Member] | Operating Segments [Member] | USA Operations [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Cost 38,417 50,573
Less: Accumulated depreciation, depletion and amortization (30,469) (39,294)
Property, plant and equipment, net 7,948 11,279
Proved Properties [Member] | Operating Segments [Member] | Canadian Operations [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Cost 21,757 19,560
Less: Accumulated depreciation, depletion and amortization (17,351) (17,163)
Property, plant and equipment, net 4,406 2,397
Unproved Properties [Member] | Operating Segments [Member] | USA Operations [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Cost 8 316
Less: Accumulated depreciation, depletion and amortization 0 0
Property, plant and equipment, net 8 316
Unproved Properties [Member] | Operating Segments [Member] | Canadian Operations [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Cost 616 118
Less: Accumulated depreciation, depletion and amortization 0 0
Property, plant and equipment, net 616 118
Other Capitalized Property Plant and Equipment [Member] | Operating Segments [Member] | USA Operations [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Cost 6 20
Less: Accumulated depreciation, depletion and amortization (2) (2)
Property, plant and equipment, net 4 18
Other Capitalized Property Plant and Equipment [Member] | Operating Segments [Member] | Canadian Operations [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Cost 129 12
Less: Accumulated depreciation, depletion and amortization (8) (5)
Property, plant and equipment, net 121 7
Other Capitalized Property Plant and Equipment [Member] | Corporate & Other [Member]    
Property, Plant and Equipment [Line Items]    
Property, Plant and Equipment, Cost 812 832
Less: Accumulated depreciation, depletion and amortization (712) (723)
Property, plant and equipment, net $ 100 $ 109