Segment Information Segment Information (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenues	$ 1,429	$ 1,444	$ 1,448	$ 1,423	$ 1,490	$ 1,460	$ 1,363	$ 1,386	$ 5,744	$ 5,699	$ 5,749
Operating Income (Loss)									(2,084)	(2,170)	(2,245)
Depreciation and Amortization									556	801	956
Capital Expenditures for Property, Plant and Equipment									(186)	(225)	(204)
Goodwill, Impairment Loss									1,917	0	0
Corporate General and Administrative									130	130	138
Long-Lived Asset Impairments									151	928	436
Gain (Loss) on Disposition of Business									53	91	10
Production Related Impairments or Charges											219
Pressure Pumping Related Charges											114
Long-lived Assets	2,188				2,893				2,188	2,893
Severance and Restructuring Charges									(126)	(183)	(280)
Litigation Charges, Net									0	10	(220)
Gain (Loss) on Disposition of Business									0	96	0
Total Assets	6,601				9,747				6,601	9,747
Inventory Write-down									80	540	269
Eastern Hemisphere [Member]
Segment Reporting Information [Line Items]
Goodwill, Impairment Loss									(537)
Total Assets	2,966				4,311				2,966	4,311
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Total Assets	513				503				513	503
Western Hemisphere [Member]
Segment Reporting Information [Line Items]
Goodwill, Impairment Loss									(1,380)
Total Assets	3,122				4,933				3,122	4,933
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues									5,744	5,699	5,749
Operating Income (Loss)									327	(252)	(564)
Depreciation and Amortization									549	795	947
Capital Expenditures for Property, Plant and Equipment									(168)	(200)	(189)
Operating Segments [Member] | Eastern Hemisphere [Member]
Segment Reporting Information [Line Items]
Revenues									2,681	2,762	2,807
Operating Income (Loss)									119	(139)	(157)
Depreciation and Amortization									333	443	501
Capital Expenditures for Property, Plant and Equipment									(87)	(130)	(134)
Operating Segments [Member] | Western Hemisphere [Member]
Segment Reporting Information [Line Items]
Revenues									3,063	2,937	2,942
Operating Income (Loss)									208	(113)	(407)
Depreciation and Amortization									216	352	446
Capital Expenditures for Property, Plant and Equipment									(81)	(70)	(55)
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Depreciation and Amortization									7	6	9
Capital Expenditures for Property, Plant and Equipment									(18)	(25)	(15)
Corporate General and Administrative									130	130	138
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Goodwill, Impairment Loss									1,917
Loss Contingency Accrual, Provision									238	1,711	1,043
Gain (Loss) on Disposition of Business										96
Severance and Restructuring Charges									(126)	183	(280)	[1]
Litigation Charges, Net										10	220
Assets, Total [Member]
Segment Reporting Information [Line Items]
Long-Lived Asset Impairments									87	506	710
Transformation Plan [Member]
Segment Reporting Information [Line Items]
Severance and Restructuring Charges									(126)
Transformation Plan [Member] | Eastern Hemisphere [Member]
Segment Reporting Information [Line Items]
Severance and Restructuring Charges									(45)
Transformation Plan [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Severance and Restructuring Charges									(54)
Transformation Plan [Member] | Western Hemisphere [Member]
Segment Reporting Information [Line Items]
Severance and Restructuring Charges									(27)
2016-17 Plan [Member]
Segment Reporting Information [Line Items]
Severance and Restructuring Charges										(183)
2016-17 Plan [Member] | Eastern Hemisphere [Member]
Segment Reporting Information [Line Items]
Severance and Restructuring Charges										(77)
2016-17 Plan [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Severance and Restructuring Charges										(36)
2016-17 Plan [Member] | Western Hemisphere [Member]
Segment Reporting Information [Line Items]
Severance and Restructuring Charges										(70)
2016 Plan [Member]
Segment Reporting Information [Line Items]
Severance and Restructuring Charges											(280)
2016 Plan [Member] | Eastern Hemisphere [Member]
Segment Reporting Information [Line Items]
Severance and Restructuring Charges											(75)
2016 Plan [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Severance and Restructuring Charges											(52)
2016 Plan [Member] | Western Hemisphere [Member]
Segment Reporting Information [Line Items]
Severance and Restructuring Charges											(153)
UNITED STATES
Segment Reporting Information [Line Items]
Revenues									1,605	1,555	$ 1,523
Long-lived Assets	750				870				750	870
Total Assets	$ 1,600				$ 2,900				$ 1,600	$ 2,900

[1] Includes restructuring charges of $280 million: $153 million in the Western Hemisphere, $75 million in the Eastern Hemisphere and $52 million in Corporate.