Restructuring Charges (Restructuring Liability) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2016 USD ($)
Severance and Other Restructuring Liabilities [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	$ 51
Restructuring Charges	150
Cash Payments	(159)
Other	(5)
Accrued balance at end of period	37
Severance and Other Restructuring Liabilities [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
Severance and Other Restructuring Liabilities [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	35
Severance and Other Restructuring Liabilities [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
2016 Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	0
Restructuring Charges	126
Cash Payments	(119)
Other	3
Accrued balance at end of period	10
2016 Plan [Member] | Employee Severance [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2016 Plan [Member] | Employee Severance [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	9
2016 Plan [Member] | Employee Severance [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
2016 Plan [Member] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	0
Restructuring Charges	24
Cash Payments	(10)
Other	(4)
Accrued balance at end of period	10
2016 Plan [Member] | Other Restructuring [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2016 Plan [Member] | Other Restructuring [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	10
2016 Plan [Member] | Other Restructuring [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2014 & 2015 Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	37
Restructuring Charges	0
Cash Payments	(26)
Other	(6)
Accrued balance at end of period	5
2014 & 2015 Plan [Member] | Employee Severance [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
2014 & 2015 Plan [Member] | Employee Severance [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	4
2014 & 2015 Plan [Member] | Employee Severance [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2014 & 2015 Plan [Member] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	14
Restructuring Charges	0
Cash Payments	(4)
Other	2
Accrued balance at end of period	12
2014 & 2015 Plan [Member] | Other Restructuring [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2014 & 2015 Plan [Member] | Other Restructuring [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	12
2014 & 2015 Plan [Member] | Other Restructuring [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
North America [Member] | Severance and Other Restructuring Liabilities [Member] | Operating Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	15
North America [Member] | 2016 Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	4
North America [Member] | 2016 Plan [Member] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	7
North America [Member] | 2014 & 2015 Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	3
North America [Member] | 2014 & 2015 Plan [Member] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
Middle East, North Africa, and Asia [Member] | Severance and Other Restructuring Liabilities [Member] | Operating Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	7
Middle East, North Africa, and Asia [Member] | 2016 Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	2
Middle East, North Africa, and Asia [Member] | 2016 Plan [Member] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
Middle East, North Africa, and Asia [Member] | 2014 & 2015 Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
Middle East, North Africa, and Asia [Member] | 2014 & 2015 Plan [Member] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	3
Europe, Sub-Sahara Africa, Russia [Member] | Severance and Other Restructuring Liabilities [Member] | Operating Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	13
Europe, Sub-Sahara Africa, Russia [Member] | 2016 Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	3
Europe, Sub-Sahara Africa, Russia [Member] | 2016 Plan [Member] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	2
Europe, Sub-Sahara Africa, Russia [Member] | 2014 & 2015 Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
Europe, Sub-Sahara Africa, Russia [Member] | 2014 & 2015 Plan [Member] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	8
Latin America [Member] | Severance and Other Restructuring Liabilities [Member] | Operating Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
Latin America [Member] | 2016 Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
Latin America [Member] | 2016 Plan [Member] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
Latin America [Member] | 2014 & 2015 Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
Latin America [Member] | 2014 & 2015 Plan [Member] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	$ 0