Restructuring Charges (Restructuring Liability) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2017 USD ($)
Severance and Other Restructuring Liabilities
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	$ 86
Restructuring Charges	94
Cash Payments	(83)
Other	(19)
Accrued balance at end of period	78
Severance and Other Restructuring Liabilities | Corporate and Research and Development
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	29
Severance and Other Restructuring Liabilities | Core Regional Segments
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	49
Severance and Other Restructuring Liabilities | Land Drilling Rigs
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2016 Plan | Employee Severance
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	52
Restructuring Charges	56
Cash Payments	(65)
Other	(4)
Accrued balance at end of period	39
2016 Plan | Employee Severance | Corporate and Research and Development
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	29
2016 Plan | Employee Severance | Core Regional Segments
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	10
2016 Plan | Employee Severance | Land Drilling Rigs
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2016 Plan | Other Restructuring
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	22
Restructuring Charges	38
Cash Payments	(15)
Other	(13)
Accrued balance at end of period	32
2016 Plan | Other Restructuring | Corporate and Research and Development
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2016 Plan | Other Restructuring | Core Regional Segments
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	32
2016 Plan | Other Restructuring | Land Drilling Rigs
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2014 & 2015 Plan | Employee Severance
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	3
Restructuring Charges	0
Cash Payments	(3)
Other	0
Accrued balance at end of period	0
2014 & 2015 Plan | Employee Severance | Corporate and Research and Development
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2014 & 2015 Plan | Employee Severance | Core Regional Segments
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2014 & 2015 Plan | Employee Severance | Land Drilling Rigs
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2014 & 2015 Plan | Other Restructuring
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	9
Restructuring Charges	0
Cash Payments	0
Other	(2)
Accrued balance at end of period	7
2014 & 2015 Plan | Other Restructuring | Corporate and Research and Development
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2014 & 2015 Plan | Other Restructuring | Core Regional Segments
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	7
2014 & 2015 Plan | Other Restructuring | Land Drilling Rigs
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
North America | Severance and Other Restructuring Liabilities | Operating Segments
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	21
North America | 2016 Plan | Employee Severance
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
North America | 2016 Plan | Other Restructuring
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	20
North America | 2014 & 2015 Plan | Employee Severance
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
North America | 2014 & 2015 Plan | Other Restructuring
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
Middle East, North Africa, and Asia | Severance and Other Restructuring Liabilities | Operating Segments
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	7
Middle East, North Africa, and Asia | 2016 Plan | Employee Severance
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	5
Middle East, North Africa, and Asia | 2016 Plan | Other Restructuring
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	2
Middle East, North Africa, and Asia | 2014 & 2015 Plan | Employee Severance
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
Middle East, North Africa, and Asia | 2014 & 2015 Plan | Other Restructuring
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
Europe, Sub-Sahara Africa, Russia | Severance and Other Restructuring Liabilities | Operating Segments
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	20
Europe, Sub-Sahara Africa, Russia | 2016 Plan | Employee Severance
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	3
Europe, Sub-Sahara Africa, Russia | 2016 Plan | Other Restructuring
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	10
Europe, Sub-Sahara Africa, Russia | 2014 & 2015 Plan | Employee Severance
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
Europe, Sub-Sahara Africa, Russia | 2014 & 2015 Plan | Other Restructuring
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	7
Latin America | Severance and Other Restructuring Liabilities | Operating Segments
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
Latin America | 2016 Plan | Employee Severance
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
Latin America | 2016 Plan | Other Restructuring
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
Latin America | 2014 & 2015 Plan | Employee Severance
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
Latin America | 2014 & 2015 Plan | Other Restructuring
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	$ 0