Restructuring Charges (Restructuring Liability) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Restructuring Reserve [Roll Forward]
Restructuring Charges	$ 41	$ 70
Severance and Other Restructuring Liabilities [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	79
Restructuring Charges	41
Cash Payments	(65)
Other	(6)
Accrued balance at end of period	49
Severance and Other Restructuring Liabilities [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	5
Severance and Other Restructuring Liabilities [Member] | North America [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	17
Severance and Other Restructuring Liabilities [Member] | MENA/ Asia Pacific [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	12
Severance and Other Restructuring Liabilities [Member] | Europe/ SSA/ Russia [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	11
Severance and Other Restructuring Liabilities [Member] | Latin America [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	3
Severance and Other Restructuring Liabilities [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	43
Severance and Other Restructuring Liabilities [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
2015 Plan [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	41
2015 Plan [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	3
2015 Plan [Member] | North America [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	8
2015 Plan [Member] | MENA/ Asia Pacific [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	6
2015 Plan [Member] | Europe/ SSA/ Russia [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	7
2015 Plan [Member] | Latin America [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	12
2015 Plan [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	33
2015 Plan [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	5
2015 Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	33
2015 Plan [Member] | Employee Severance [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	0
2015 Plan [Member] | Employee Severance [Member] | North America [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	16
2015 Plan [Member] | Employee Severance [Member] | MENA/ Asia Pacific [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	6
2015 Plan [Member] | Employee Severance [Member] | Europe/ SSA/ Russia [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	7
2015 Plan [Member] | Employee Severance [Member] | Latin America [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	3
2015 Plan [Member] | Employee Severance [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	32
2015 Plan [Member] | Employee Severance [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at end of period	1
2015 Plan [Member] | One-time Termination Benefits [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	53
Restructuring Charges	40
Cash Payments	(58)
Other	(2)
Accrued balance at end of period	33
2015 Plan [Member] | One-time Termination Benefits [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	3
2015 Plan [Member] | One-time Termination Benefits [Member] | North America [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	8
2015 Plan [Member] | One-time Termination Benefits [Member] | MENA/ Asia Pacific [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	5
2015 Plan [Member] | One-time Termination Benefits [Member] | Europe/ SSA/ Russia [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	7
2015 Plan [Member] | One-time Termination Benefits [Member] | Latin America [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	12
2015 Plan [Member] | One-time Termination Benefits [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	32
2015 Plan [Member] | One-time Termination Benefits [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	5
2015 Plan [Member] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	0
Restructuring Charges	1
Cash Payments	0
Other	0
Accrued balance at end of period	1
2015 Plan [Member] | Other Restructuring [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	0
Accrued balance at end of period	0
2015 Plan [Member] | Other Restructuring [Member] | North America [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	0
Accrued balance at end of period	0
2015 Plan [Member] | Other Restructuring [Member] | MENA/ Asia Pacific [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	1
Accrued balance at end of period	1
2015 Plan [Member] | Other Restructuring [Member] | Europe/ SSA/ Russia [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	0
Accrued balance at end of period	0
2015 Plan [Member] | Other Restructuring [Member] | Latin America [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	0
Accrued balance at end of period	0
2015 Plan [Member] | Other Restructuring [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	1
Accrued balance at end of period	1
2015 Plan [Member] | Other Restructuring [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges	0
Accrued balance at end of period	0
2014 Plan [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		70
2014 Plan [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		16
2014 Plan [Member] | North America [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		9
2014 Plan [Member] | MENA/ Asia Pacific [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		4
2014 Plan [Member] | Europe/ SSA/ Russia [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		19
2014 Plan [Member] | Latin America [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		19
2014 Plan [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		51
2014 Plan [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		3
2014 Plan [Member] | Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		66
Accrued balance at end of period	6
2014 Plan [Member] | Employee Severance [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		16
Accrued balance at end of period	5
2014 Plan [Member] | Employee Severance [Member] | North America [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		9
Accrued balance at end of period	0
2014 Plan [Member] | Employee Severance [Member] | MENA/ Asia Pacific [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		4
Accrued balance at end of period	1
2014 Plan [Member] | Employee Severance [Member] | Europe/ SSA/ Russia [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		15
Accrued balance at end of period	0
2014 Plan [Member] | Employee Severance [Member] | Latin America [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		19
Accrued balance at end of period	0
2014 Plan [Member] | Employee Severance [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		47
Accrued balance at end of period	1
2014 Plan [Member] | Employee Severance [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		3
Accrued balance at end of period	0
2014 Plan [Member] | One-time Termination Benefits [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] | Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Accrued balance at beginning of period	12
Restructuring Charges	0	4
Cash Payments	(1)
Other	(2)
Accrued balance at end of period	9
2014 Plan [Member] | Other Restructuring [Member] | Corporate and Research and Development [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		0
Accrued balance at end of period	0
2014 Plan [Member] | Other Restructuring [Member] | North America [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		0
Accrued balance at end of period	1
2014 Plan [Member] | Other Restructuring [Member] | MENA/ Asia Pacific [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		0
Accrued balance at end of period	4
2014 Plan [Member] | Other Restructuring [Member] | Europe/ SSA/ Russia [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		4
Accrued balance at end of period	4
2014 Plan [Member] | Other Restructuring [Member] | Latin America [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		0
Accrued balance at end of period	0
2014 Plan [Member] | Other Restructuring [Member] | Core Regional Segments [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		4
Accrued balance at end of period	9
2014 Plan [Member] | Other Restructuring [Member] | Drilling Rigs [Member]
Restructuring Reserve [Roll Forward]
Restructuring Charges		0
Accrued balance at end of period	$ 0