v3.19.3.a.u2
Impairments (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Impaired Assets to be Disposed of by Method Other than Sale [Line Items]      
Asset Impairment Charges $ 405 $ 27 $ 6,601
Alaska Segment [Member] | Operating Segments [Member]      
Impaired Assets to be Disposed of by Method Other than Sale [Line Items]      
Asset Impairment Charges 0 20 180
Lower 48 Segment [Member] | Operating Segments [Member]      
Impaired Assets to be Disposed of by Method Other than Sale [Line Items]      
Asset Impairment Charges 402 63 3,969
Canada Segment [Member] | Operating Segments [Member]      
Impaired Assets to be Disposed of by Method Other than Sale [Line Items]      
Asset Impairment Charges 2 9 22
Europe and North Africa Segment [Member] | Operating Segments [Member]      
Impaired Assets to be Disposed of by Method Other than Sale [Line Items]      
Asset Impairment Charges 1 (79) 46
Asia Pacific and Middle East Segment [Member] | Operating Segments [Member]      
Impaired Assets to be Disposed of by Method Other than Sale [Line Items]      
Asset Impairment Charges $ 0 $ 14 $ 2,384