Segment Information Narrative (Details) $ in Millions	3 Months Ended									12 Months Ended
	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2017 USD ($) unit	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Asset Impairment Charges											$ 436
Number of Reportable Segments | unit										2
Long-Lived Asset Impairments and Other Charges										$ 928	436	$ 638
Production Related Impairments or Charges											219
Pressure Pumping Related Charges											114	63
Fair Value Adjustment of Warrants										(86)	(16)	0
Supply Agreement Charges related to Non-Core Business Divestiture												67
Restructuring Charges										183	280	232
Revenue, Net	$ 1,490	$ 1,460	$ 1,363	$ 1,386	$ 1,406	$ 1,356	$ 1,402	$ 1,585		5,699	5,749	9,433
Professional Fees												17
Facility Closure Fees												24
Other Nonrecurring (Income) Expense	1,600	$ 35	$ 108	$ 134	245	$ 771	347	$ 285				11
Bad Debt Expense									$ 31	8	69	48
Increase (decrease) in accounts receivable										29	(214)	(1,031)
Assets	9,747				12,664					9,747	12,664
Deferred tax assets for long-lived assets					36				$ 81		36	81
Financing Receivable, Allowance for Credit Losses, Write-downs							$ 84				76
Allowance for Doubtful Accounts Receivable, Write-offs										230	0	0
Asset Write Down and Other										1,664	1,043	768
UNITED STATES
Segment Reporting Information [Line Items]
Revenue, Net										1,555	1,523	2,864
Assets	2,900				3,300					2,900	3,300
2016 Plan [Member]
Segment Reporting Information [Line Items]
Restructuring Charges											280
2015 Plan [Member]
Segment Reporting Information [Line Items]
Restructuring Charges												232
Operating Segments [Member]
Segment Reporting Information [Line Items]
Production Related Impairments or Charges												223
Revenue, Net										5,699	5,749	9,433
Western Hemisphere [Member]
Segment Reporting Information [Line Items]
Asset Impairment Charges										135
Production Related Impairments or Charges												127
Bad Debt Expense												29
Assets	4,933				6,167					4,933	6,167
Western Hemisphere [Member] | 2016 Plan [Member]
Segment Reporting Information [Line Items]
Restructuring Charges											153
Western Hemisphere [Member] | 2015 Plan [Member]
Segment Reporting Information [Line Items]
Restructuring Charges												94
Western Hemisphere [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue, Net										2,937	2,942	5,276
Drilling Rigs [Member]
Segment Reporting Information [Line Items]
Long-Lived Asset Impairments and Other Charges												255
Eastern Hemisphere [Member]
Segment Reporting Information [Line Items]
Asset Impairment Charges										37
Production Related Impairments or Charges												96
Bad Debt Expense												19
Assets	4,311				5,491					4,311	5,491
Eastern Hemisphere [Member] | 2016 Plan [Member]
Segment Reporting Information [Line Items]
Restructuring Charges											75
Eastern Hemisphere [Member] | 2015 Plan [Member]
Segment Reporting Information [Line Items]
Restructuring Charges												123
Eastern Hemisphere [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue, Net										2,762	2,807	4,157
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Assets	$ 503				$ 1,006					503	1,006
Corporate, Non-Segment [Member] | 2016 Plan [Member]
Segment Reporting Information [Line Items]
Restructuring Charges											52
Corporate, Non-Segment [Member] | 2015 Plan [Member]
Segment Reporting Information [Line Items]
Restructuring Charges												$ 15
Assets, Total [Member]
Segment Reporting Information [Line Items]
Long-Lived Asset Impairments and Other Charges										$ 506	$ 710