Income Taxes (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Disclosure [Abstract]
Income Tax Expense (Benefit)		$ 76	$ 18	$ 193	$ (265)
Income (loss) from continuing operations before income taxes		316	(1)	834	(2,980)
Impairments and other charges	[1]	12	133	12	3,353
Loss on early extinguishment of debt		$ 0	$ 0	$ 0	$ (168)	[2]

[1] For the three and nine months ended September 30, 2021, amount includes a $42 million charge attributable to Completions and Production, a $9 million charge attributable to Drilling and Evaluation, and a $39 million net gain attributable to Corporate and other. For the three and nine months ended September 30, 2020, amount includes $90 million and $2.1 billion attributable to Completion and Production, $40 million and $1.2 billion attributable to Drilling and Evaluation, and $3 million and $44 million attributable to Corporate and other, respectively.

[2] For the nine months ended September 30, 2020, amount includes a $168 million loss on extinguishment of debt related to the early repurchase of senior notes.