Restructuring Charges (Restructuring Liability) (Details) $ in Millions	9 Months Ended
	Sep. 30, 2015 USD ($)
Severance and Other Restructuring Liabilities [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	$ 79
Restructuring Charges	108
Cash Payments	(150)
Other	(3)
Accrued balance at end of period	34
Severance and Other Restructuring Liabilities [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	9
Severance and Other Restructuring Liabilities [Member] | North America [Member] | Operating Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	3
Severance and Other Restructuring Liabilities [Member] | MENA/ Asia Pacific [Member] | Operating Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	10
Severance and Other Restructuring Liabilities [Member] | Europe/ SSA/ Russia [Member] | Operating Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	11
Severance and Other Restructuring Liabilities [Member] | Latin America [Member] | Operating Segments [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	25
Severance and Other Restructuring Liabilities [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2015 Plan | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	53
Restructuring Charges	99
Cash Payments	(132)
Other	(2)
Accrued balance at end of period	18
2015 Plan | Employee Severance [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	4
2015 Plan | Employee Severance [Member] | North America [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
2015 Plan | Employee Severance [Member] | MENA/ Asia Pacific [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	4
2015 Plan | Employee Severance [Member] | Europe/ SSA/ Russia [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	8
2015 Plan | Employee Severance [Member] | Latin America [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
2015 Plan | Employee Severance [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	14
2015 Plan | Employee Severance [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2015 Plan | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	0
Restructuring Charges	9
Cash Payments	(8)
Other	3
Accrued balance at end of period	4
2015 Plan | Other Restructuring [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2015 Plan | Other Restructuring [Member] | North America [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	2
2015 Plan | Other Restructuring [Member] | MENA/ Asia Pacific [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2015 Plan | Other Restructuring [Member] | Europe/ SSA/ Russia [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	2
2015 Plan | Other Restructuring [Member] | Latin America [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2015 Plan | Other Restructuring [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	4
2015 Plan | Other Restructuring [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2014 Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	14
Restructuring Charges	0
Cash Payments	(6)
Other	(2)
Accrued balance at end of period	6
2014 Plan [Member] | Employee Severance [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	5
2014 Plan [Member] | Employee Severance [Member] | North America [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2014 Plan [Member] | Employee Severance [Member] | MENA/ Asia Pacific [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
2014 Plan [Member] | Employee Severance [Member] | Europe/ SSA/ Russia [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2014 Plan [Member] | Employee Severance [Member] | Latin America [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2014 Plan [Member] | Employee Severance [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
2014 Plan [Member] | Employee Severance [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2014 Plan [Member] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	12
Restructuring Charges	0
Cash Payments	(4)
Other	(2)
Accrued balance at end of period	6
2014 Plan [Member] | Other Restructuring [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2014 Plan [Member] | Other Restructuring [Member] | North America [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2014 Plan [Member] | Other Restructuring [Member] | MENA/ Asia Pacific [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	5
2014 Plan [Member] | Other Restructuring [Member] | Europe/ SSA/ Russia [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
2014 Plan [Member] | Other Restructuring [Member] | Latin America [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2014 Plan [Member] | Other Restructuring [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	6
2014 Plan [Member] | Other Restructuring [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	$ 0