v3.19.3.a.u2
Property, Plant And Equipment And Asset Retirement Obligations (Narrative) (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Property, Plant and Equipment [Line Items]      
Asset impairment charges, before-tax $ 100 $ 700 $ 2,000
Accumulated depreciation and depletion 233,684 230,089  
Interest capitalized 731 652 $ 749
Long-term asset retirement obligations $ 10,279 $ 11,185