Restructuring Charges (Restructuring Charges) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring Charges	$ 59	$ 280	$ 232	$ 331
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs				172
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs				159
Severance and Other Restructuring Liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges				331
Restructuring Reserve		86	51
Severance and Other Restructuring Liabilities [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		30
Severance and Other Restructuring Liabilities [Member] | Operating Segments [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		27
Severance and Other Restructuring Liabilities [Member] | Operating Segments [Member] | Middle East/North Africa/Asia [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		12
Severance and Other Restructuring Liabilities [Member] | Operating Segments [Member] | Europe/Sub-Sahara Africa/Russia [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		16
Severance and Other Restructuring Liabilities [Member] | Operating Segments [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		0
Severance and Other Restructuring Liabilities [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		55
Severance and Other Restructuring Liabilities [Member] | Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		1
2016 Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		280
2016 Plan [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		52
2016 Plan [Member] | Operating Segments [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		96
2016 Plan [Member] | Operating Segments [Member] | Middle East/North Africa/Asia [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		33
2016 Plan [Member] | Operating Segments [Member] | Europe/Sub-Sahara Africa/Russia [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		36
2016 Plan [Member] | Operating Segments [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		56
2016 Plan [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs		196
Restructuring Reserve		52	0
2016 Plan [Member] | Employee Severance [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs		38
Restructuring Reserve		8
2016 Plan [Member] | Employee Severance [Member] | Middle East/North Africa/Asia [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs		29
Restructuring Reserve		6
2016 Plan [Member] | Employee Severance [Member] | Europe/Sub-Sahara Africa/Russia [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs		27
Restructuring Reserve		7
2016 Plan [Member] | Employee Severance [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs		43
Restructuring Reserve		0
2016 Plan [Member] | Employee Severance [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs		52
Restructuring Reserve		30
2016 Plan [Member] | Employee Severance [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs		137
Restructuring Reserve		21
2016 Plan [Member] | Employee Severance [Member] | Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs		7
Restructuring Reserve		1
2016 Plan [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs		84
Restructuring Reserve		22	0
2016 Plan [Member] | Other Restructuring [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs		58
Restructuring Reserve		16
2016 Plan [Member] | Other Restructuring [Member] | Middle East/North Africa/Asia [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs		4
Restructuring Reserve		4
2016 Plan [Member] | Other Restructuring [Member] | Europe/Sub-Sahara Africa/Russia [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs		9
Restructuring Reserve		2
2016 Plan [Member] | Other Restructuring [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs		13
Restructuring Reserve		0
2016 Plan [Member] | Other Restructuring [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs		0
Restructuring Reserve		0
2016 Plan [Member] | Other Restructuring [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs		84
Restructuring Reserve		22
2016 Plan [Member] | Other Restructuring [Member] | Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs		0
Restructuring Reserve		0
2016 Plan [Member] | Severance and Other Restructuring Liabilities [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges		$ 221
2015 Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			232
2015 Plan [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			16
2015 Plan [Member] | Operating Segments [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			52
2015 Plan [Member] | Operating Segments [Member] | Middle East/North Africa/Asia [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			56
2015 Plan [Member] | Operating Segments [Member] | Europe/Sub-Sahara Africa/Russia [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			56
2015 Plan [Member] | Operating Segments [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			40
2015 Plan [Member] | Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			12
2015 Plan [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs			149	58
Restructuring Charges			58
2015 Plan [Member] | Employee Severance [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs			28	32
2015 Plan [Member] | Employee Severance [Member] | Middle East/North Africa/Asia [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs			21	8
2015 Plan [Member] | Employee Severance [Member] | Europe/Sub-Sahara Africa/Russia [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs			34	5
2015 Plan [Member] | Employee Severance [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs			38	12
2015 Plan [Member] | Employee Severance [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs			16	1
2015 Plan [Member] | Employee Severance [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs			121	57
2015 Plan [Member] | Employee Severance [Member] | Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs			12	0
2015 Plan [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs			83	0
2015 Plan [Member] | Other Restructuring [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs			24	0
2015 Plan [Member] | Other Restructuring [Member] | Middle East/North Africa/Asia [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs			35	0
2015 Plan [Member] | Other Restructuring [Member] | Europe/Sub-Sahara Africa/Russia [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs			22	0
2015 Plan [Member] | Other Restructuring [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs			2	0
2015 Plan [Member] | Other Restructuring [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs			0	0
2015 Plan [Member] | Other Restructuring [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs			83	0
2015 Plan [Member] | Other Restructuring [Member] | Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs			0	0
2015 Plan [Member] | Severance and Other Restructuring Liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			58	58
2015 Plan [Member] | Severance and Other Restructuring Liabilities [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges				1
2015 Plan [Member] | Severance and Other Restructuring Liabilities [Member] | Operating Segments [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges				32
2015 Plan [Member] | Severance and Other Restructuring Liabilities [Member] | Operating Segments [Member] | Middle East/North Africa/Asia [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges				8
2015 Plan [Member] | Severance and Other Restructuring Liabilities [Member] | Operating Segments [Member] | Europe/Sub-Sahara Africa/Russia [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges				5
2015 Plan [Member] | Severance and Other Restructuring Liabilities [Member] | Operating Segments [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges				12
2015 Plan [Member] | Severance and Other Restructuring Liabilities [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges			$ 204	57
2015 Plan [Member] | Severance and Other Restructuring Liabilities [Member] | Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges				0
2014 Plan [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs				114
2014 Plan [Member] | Employee Severance [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs				17
2014 Plan [Member] | Employee Severance [Member] | Middle East/North Africa/Asia [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs				19
2014 Plan [Member] | Employee Severance [Member] | Europe/Sub-Sahara Africa/Russia [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs				17
2014 Plan [Member] | Employee Severance [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs				29
2014 Plan [Member] | Employee Severance [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs				27
2014 Plan [Member] | Employee Severance [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs				82
2014 Plan [Member] | Employee Severance [Member] | Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Severance Costs				5
2014 Plan [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs				159
Restructuring Charges				24
2014 Plan [Member] | Other Restructuring [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs				27
2014 Plan [Member] | Other Restructuring [Member] | Middle East/North Africa/Asia [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs				106
2014 Plan [Member] | Other Restructuring [Member] | Europe/Sub-Sahara Africa/Russia [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs				13
2014 Plan [Member] | Other Restructuring [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs				7
2014 Plan [Member] | Other Restructuring [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs				2
2014 Plan [Member] | Other Restructuring [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs				153
2014 Plan [Member] | Other Restructuring [Member] | Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Other Restructuring Costs				4
2014 Plan [Member] | Severance and Other Restructuring Liabilities [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges				273
2014 Plan [Member] | Severance and Other Restructuring Liabilities [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges				29
2014 Plan [Member] | Severance and Other Restructuring Liabilities [Member] | Operating Segments [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges				44
2014 Plan [Member] | Severance and Other Restructuring Liabilities [Member] | Operating Segments [Member] | Middle East/North Africa/Asia [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges				125
2014 Plan [Member] | Severance and Other Restructuring Liabilities [Member] | Operating Segments [Member] | Europe/Sub-Sahara Africa/Russia [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges				30
2014 Plan [Member] | Severance and Other Restructuring Liabilities [Member] | Operating Segments [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges				36
2014 Plan [Member] | Severance and Other Restructuring Liabilities [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges				235
2014 Plan [Member] | Severance and Other Restructuring Liabilities [Member] | Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Charges				$ 9