Income Taxes (Details) - USD ($) $ in Millions		3 Months Ended				12 Months Ended
		Dec. 31, 2018		Mar. 31, 2018		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Current income taxes:
Federal						$ 19		$ 40		$ 737
Foreign						(428)		(423)		(415)
State						(15)		(14)		35
Total current						424		397		(357)
Deferred income taxes:
Federal						286		(678)		1,343
Foreign						9		(31)		77
State						(28)		(25)		81
Total deferred						267		(734)		1,501
Income tax benefit (provision)		$ 306				(157)		(1,131)		1,858
The United States and foreign components of income from continuing operations before income taxes [Abstract]
United States						1,097		694		(6,636)
Foreign						717		(12)		(989)
Income (loss) from continuing operations before income taxes						$ 1,814		$ 682		$ (7,625)
Reconciliations between the actual provision for income taxes on continuing operations [Abstract]
United States statutory rate						21.00%		35.00%		35.00%
Impact of U.S. tax reform						(2.60%)		113.00%		0.00%
Venezuela adjustment						5.70%		36.60%		0.00%
Impact of foreign income taxed at different rates						(3.00%)		(18.30%)		(3.20%)
Valuation allowance against tax assets						(16.20%)		(6.20%)		(2.10%)
Undistributed foreign earnings						0.00%		3.80%		(5.10%)
Adjustments of prior year taxes						2.00%		(2.30%)		0.20%
State income taxes						1.90%		1.70%		1.00%
Domestic manufacturing deduction						0.00%		0.00%		(1.30%)
Non-deductible acquisition costs						0.00%		0.00%		0.60%
Other items, net						(0.10%)		2.50%		(0.70%)
Total effective tax rate on continuing operations						8.70%		165.80%		24.40%
Impairments and other charges	[1]					$ 265		$ 647		$ 3,357
Gross deferred tax assets:
Net operating loss carryforwards		1,466				1,466		1,370
Foreign tax credit carryforwards		728				728		828
Employee compensation and benefits		242				242		263
Accrued Liabilities		101				101		97
Other		404				404		416
Total gross deferred tax assets		2,941				2,941		2,974
Gross deferred tax liabilities:
Depreciation and amortization		635				635		315
Undistributed Foreign Earnings		2				2		242
Other		64				64		56
Total gross deferred tax liabilities		701				701		613
Valuation allowances		913				913		1,173
Net deferred income tax asset		1,327				1,327		1,188
Unrecognized Tax Benefits
Beginning Balance				$ 333	[2]	333	[2]	427		322
Change in prior year tax positions						32				44
Change in prior year tax positions								(108)
Change in current year tax positions						63		24		129
Cash settlements with taxing authorities						(7)		(6)		(62)
Lapse of statute of limitations						(4)		(4)		(6)
Ending balance		417	[2],[3]			417	[2],[3]	333	[2]	427
Interest and Penalties
Beginning balance				60		60		61		47
Change in prior year tax positions						11		0		20
Change in current year tax positions						0		2		3
Cash settlements with taxing authorities						(2)		0		(8)
Lapse of statute of limitations						(2)		(3)		(1)
Ending balance		67				67		60		61
Remaining balance if resolved in our favor would positively impact the effective tax rate		399				399		319
Portion of unrecognized tax benefits that could be resolved within the next 12 months		21				21
Impairments and other charges				265		265		647		$ 3,357	[1]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount		47
Foreign Country
Income Tax Contingency [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration		1,500				1,500
Years 2018-2022 [Domain]
Income Tax Contingency [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration		168				168
Years 2024-2028 [Domain]
Income Tax Contingency [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration		180				180
Deferred Tax Assets, Tax Credit Carryforwards, Research and Foreign That Expire		805				805
Years 2029-2038 [Domain]
Income Tax Contingency [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration		786				786
Deferred Tax Assets, Tax Credit Carryforwards, Research and Foreign That Expire		138				138
VENEZUELA
Reconciliations between the actual provision for income taxes on continuing operations [Abstract]
Impairments and other charges	[1]							647
Interest and Penalties
Accrued taxes portion of Venezuela investment write-down				$ 47
All Other Countries [Domain]
Interest and Penalties
Remaining balance if resolved in our favor would positively impact the effective tax rate		$ 18				$ 18		$ 9

[1] Impairments and other charges are as follows: -For the year ended December 31, 2018, the aggregate charge of $265 million represents a write-down of all of our remaining investment in Venezuela, consisting of receivables, fixed assets, inventory and other assets and liabilities. -For the year ended December 31, 2017, the aggregate charge of $647 million represents a fair market value adjustment on our existing promissory note with our primary customer in Venezuela and a full reserve against our other accounts receivable with this customer. -For the year ended December 31, 2016, the aggregate charge of $3.4 billion consisted of fixed asset impairments and write-offs, inventory write-downs, impairments of intangible assets, severance costs, country and facility closures, and other charges related to the energy downturn. This included $2.1 billion attributable to Completion and Production, $1.2 billion attributable to Drilling and Evaluation and $10 million attributable to Corporate and other.

[2] Includes $18 million as of December 31, 2018 and $9 million as of December 31, 2017 in foreign unrecognized tax benefits that would give rise to a United States tax credit. As of December 31, 2018 and December 31, 2017, approximately $399 million and $319 million, respectively, of unrecognized tax benefits would positively impact the effective tax rate and be recognized as additional tax benefits in our statement of operations if resolved in our favor.

[3] Includes $21 million that could be resolved within the next 12 months.