Income Taxes (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Income Taxes [Abstract]        
Income Tax Expense (Benefit) $ 59 $ 37 $ 1,836 $ 207
Income (loss) from continuing operations before income taxes $ (52) $ (90) (7,450) (843)
Effective Income Tax Rate Reconciliation, Percent 114.30% 40.80%    
Other Tax Expense (Benefit) $ 29      
Impairments and other charges [1] $ 0 $ 381 $ 3,189 $ 1,895
[1] Impairments and other charges are as follows:-For the three months ended September 30, 2015, includes $228 million attributable to Completion and Production, $138 million attributable to Drilling and Evaluation, and $15 million attributable to Corporate and other. -For the nine months ended September 30, 2016, includes $2.0 billion attributable to Completion and Production, $1.1 billion attributable to Drilling and Evaluation, and $8 million attributable to Corporate and other. -For the nine months ended September 30, 2015, includes $949 million attributable to Completion and Production, $865 million attributable to Drilling and Evaluation, and $81 million attributable to Corporate and other.