Segment Information (Narrative) (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2016		Mar. 31, 2015
Segment Reporting Information [Line Items]
Revenues		$ 1,585		$ 2,794
Pressure Pumping Related Charges		20
Supply Agreement Charges related to Non-Core Business Divestiture		15
Loss from Catastrophes		14
Severance, asset impairment and other restructuring charges		77		41
Professional Fees		6		13
Other nonrecurring (income) expense		2
Operating Income (Loss)		(447)		50
Depreciation and Amortization		250		316
Research and Development		45		64
Litigation Charges, Net		67		0
Gain (Loss) on Disposition of Business		(1)		3
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues		1,585		2,794
Operating Income (Loss)		(157)		229
Depreciation and Amortization		246		310
Operating Segments [Member] | Core Regional Segments [Member]
Segment Reporting Information [Line Items]
Revenues		1,466		2,599
Operating Income (Loss)		(131)		219
Depreciation and Amortization		224		281
Operating Segments [Member] | Drilling Rigs [Member]
Segment Reporting Information [Line Items]
Revenues		119		195
Operating Income (Loss)		(26)		10
Depreciation and Amortization		22		29
Corporate and Research and Development [Member]
Segment Reporting Information [Line Items]
Depreciation and Amortization		4		6
Research and Development		88		120
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges		77	[1]	41	[2]
Litigation Charges, Net	[3]	67
Gain (Loss) on Disposition of Business		(1)		3
Other Nonoperating Expense		8	[3]	21	[4]
Latin America [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues		305		486
Operating Income (Loss)		44		98
Depreciation and Amortization		61		61
Europe, Sub-Sahara Africa, Russia [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues		257		417
Operating Income (Loss)		(1)		71
Depreciation and Amortization		48		50
Middle East, North Africa, and Asia [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues		361		533
Operating Income (Loss)		(46)		60
Depreciation and Amortization		61		65
North America [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues		543		1,163
Operating Income (Loss)		(128)		(10)
Depreciation and Amortization		$ 54		105
2015 Plan
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges				41
2015 Plan | Core Regional Segments [Member]
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges				33
2015 Plan | Drilling Rigs [Member]
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges				5
2015 Plan | Corporate and Research and Development [Member]
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges				3
2015 Plan | Latin America [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges				12
2015 Plan | Europe, Sub-Sahara Africa, Russia [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges				7
2015 Plan | Middle East, North Africa, and Asia [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges				6
2015 Plan | North America [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Severance, asset impairment and other restructuring charges				$ 8

[1] Includes restructuring charges of $77 million: $24 million in North America, $15 million in Europe/SSA/Russia, $15 million in Latin America, $10 million in Corporate and Research and Development, $9 million in MENA/Asia Pacific, and $4 million in Land Drilling Rigs.

[2] Includes restructuring charges of $41 million: $8 million in North America, $6 million in MENA/Asia Pacific, $7 million in Europe/SSA/Russia, $12 million in Latin America, $5 million in Land Drilling Rigs and $3 million in Corporate and Research and Development.

[3] Includes professional and other fees of $6 million and divestiture related charges of $2 million.

[4] Includes professional fees of $13 million related to the divestiture of our non-core businesses, restatement related litigation, post-settlement monitor and auditor expenses and other charges of $8 million.