Income Taxes (Details) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Current income taxes:
Current Federal Tax Expense (Benefit)						$ 40		$ 737		$ 635
Current Foreign Tax Expense (Benefit)						(423)		(415)		(636)
Current State Tax Expense (Benefit)						(14)		35		51
Total current						397		(357)		(50)
Deferred income taxes:
Federal						(678)		1,343		(18)
Foreign						(31)		77		262
State						(25)		81		(20)
Total deferred						(734)		1,501		224
Income tax benefit (provision)						(1,131)		1,858		274
The United States and foreign components of income from continuing operations before income taxes [Abstract]
United States						694		(6,636)		(1,560)
Foreign						(12)		(989)		624
Income (loss) from continuing operations before income taxes						$ 682		$ (7,625)		$ (936)
Reconciliations between the actual provision for income taxes on continuing operations [Abstract]
United States statutory rate						35.00%		35.00%		35.00%
Impact of U.S. tax reform						113.00%		0.00%		0.00%
Venezuela receivables adjustments						36.60%		(0.00%)		(7.50%)
Impact of foreign income taxed at different rates						(18.30%)		(3.20%)		17.00%
Valuation allowance against tax assets						(6.20%)		(2.10%)		(8.30%)
Undistributed foreign earnings						3.80%		(5.10%)		0.00%
Adjustments of prior year taxes						(2.30%)		0.20%		1.30%
State income taxes						1.70%		1.00%		2.00%
Domestic manufacturing deduction						0.00%		(1.30%)		0.00%
Non-deductible acquisition costs						0.00%		0.60%		(4.50%)
Other items, net						2.50%		(0.70%)		(5.70%)
Total effective tax rate on continuing operations						165.80%		24.40%		29.30%
Impairments and other charges	[1]					$ 647		$ 3,357		$ 2,177
Gross deferred tax assets:
Net operating loss carryforwards		$ 1,370				1,370		1,647
Foreign tax credit carryforwards		828				828		648
Employee compensation and benefits		263				263		352
Accrued Liabilities		97				97		325
Other		416				416		536
Total gross deferred tax assets		2,974				2,974		3,508
Gross deferred tax liabilities:
Depreciation and amortization		315				315		585
Deferred Tax Liabilities, Undistributed Foreign Earnings		242				242		406
Other		56				56		145
Total gross deferred tax liabilities		613				613		1,136
Valuation allowances		1,173				1,173		453
Net deferred income tax asset		1,188				1,188		1,919
Unrecognized Tax Benefits
Beginning Balance				$ 333	[2],[3]	427	[3]	322		314
Change in prior year tax positions						(108)				(33)
Change in prior year tax positions								44
Change in current year tax positions						24		129		62
Cash settlements with taxing authorities						(6)		(62)		(16)
Lapse of statute of limitations						(4)		(6)		(5)
Ending balance		333	[2],[3]			333	[2],[3]	427	[3]	322
Interest and Penalties
Beginning balance				$ 60		61		47		56
Change in prior year tax positions						0		20		7
Change in current year tax positions						2		3		1
Cash settlements with taxing authorities						0		(8)		(15)
Lapse of statute of limitations						(3)		(1)		(2)
Ending balance		60				60		61		$ 47
Remaining balance if resolved in our favor would positively impact the effective tax rate		319				319		257
Portion of unrecognized tax benefits that could be resolved within the next 12 months		23				23
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount		283				770
Effective Income Tax Rate Reconciliation, Repatriation of Foreign Earnings, Amount		305
Income Tax Expense (Benefit), Continuing Operations, Adjustment of Deferred Tax (Asset) Liability		130
Tax Credit Carryforward, Valuation Allowance		575				575
Other Deductions or Allowable Credits		40				40
Domestic Tax Authority [Member]
Gross deferred tax liabilities:
Deferred Tax Liabilities, Undistributed Foreign Earnings		435				435
Foreign Country
Income Tax Contingency [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration		1,400				1,400
Years 2018-2022 [Domain]
Income Tax Contingency [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration		161				161
Years 2023-2027 [Domain]
Income Tax Contingency [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration		160				160
Deferred Tax Assets, Tax Credit Carryforwards, Research and Foreign That Expire		911				911
Years 2028-2037 [Domain]
Income Tax Contingency [Line Items]
Deferred Tax Assets, Operating Loss Carryforwards, Subject to Expiration		693				693
Deferred Tax Assets, Tax Credit Carryforwards, Research and Foreign That Expire		102				102
VENEZUELA
Reconciliations between the actual provision for income taxes on continuing operations [Abstract]
Impairments and other charges	[1]					647
All Other Countries [Domain]
Interest and Penalties
Remaining balance if resolved in our favor would positively impact the effective tax rate		$ 9				$ 9		$ 84
Subsequent Event [Member]
Reconciliations between the actual provision for income taxes on continuing operations [Abstract]
United States statutory rate				21.00%

[1] Impairments and other charges are as follows:-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, includes $2.1 billion attributable to Completion and Production, $1.2 billion attributable to Drilling and Evaluation and $10 million attributable to Corporate and other. -For the year ended December 31, 2015, includes $1.1 billion attributable to Completion and Production, $1.0 billion attributable to Drilling and Evaluation and $88 million attributable to Corporate and other.

[2] Includes $23 million that could be resolved within the next 12 months.

[3] Includes $9 million as of December 31, 2017 and $84 million as of December 31, 2016 in foreign unrecognized tax benefits that would give rise to a United States tax credit. As of December 31, 2017 and December 31, 2016, approximately $319 million and $257 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.