Segment Information (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges	$ 34	$ 22	$ 140	$ 150
Asset Impairment Charges		436	0	436
Inventory Charges			66	213
Production Related Impairments or Charges		198
Allowance for Doubtful Accounts Receivable, Write-offs		62		62
Financing Receivable, Allowance for Credit Losses, Write-downs				84
Long-Lived Asset Impairments			0	436
Pressure Pumping Related Charges				20
Supply Agreement Charges related to Non-Core Business Divestiture				15
Other Asset Impairment Charges		44		121
2016 Plan
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges	34	22	140	150
2016 Plan | Drilling Rigs
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges	0	0	2	5
2016 Plan | Corporate and Research and Development
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges	2	2	29	14
2016 Plan | Europe, Sub-Sahara Africa, Russia | Operating Segments
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges	2	0	31	25
2016 Plan | North America | Operating Segments
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges	1	5	24	44
2016 Plan | Latin America | Operating Segments
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges	9	10	25	37
2016 Plan | Middle East, North Africa, and Asia | Operating Segments
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges	$ 20	$ 5	$ 29	$ 25