Restructuring Charges (Restructuring Charges) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	$ 41	$ 70
2014 Plan [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges		70
2014 Plan [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges		16
2014 Plan [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges		9
2014 Plan [Member] | MENA/ Asia Pacific [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges		4
2014 Plan [Member] | Europe/ SSA/ Russia [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges		19
2014 Plan [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges		19
2014 Plan [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges		51
2014 Plan [Member] | Land Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges		3
2014 Plan [Member] | One-time Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	6		14
Severance, asset impairment and other restructuring charges	0
2014 Plan [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	9		12
Severance, asset impairment and other restructuring charges	0	4
2014 Plan [Member] | Other Restructuring [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0
Severance, asset impairment and other restructuring charges		0
2014 Plan [Member] | Other Restructuring [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	1
Severance, asset impairment and other restructuring charges		0
2014 Plan [Member] | Other Restructuring [Member] | MENA/ Asia Pacific [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	4
Severance, asset impairment and other restructuring charges		0
2014 Plan [Member] | Other Restructuring [Member] | Europe/ SSA/ Russia [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	4
Severance, asset impairment and other restructuring charges		4
2014 Plan [Member] | Other Restructuring [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0
Severance, asset impairment and other restructuring charges		0
2014 Plan [Member] | Other Restructuring [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	9
Severance, asset impairment and other restructuring charges		4
2014 Plan [Member] | Other Restructuring [Member] | Land Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0
Severance, asset impairment and other restructuring charges		0
2014 Plan [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	6
Severance, asset impairment and other restructuring charges		66
2014 Plan [Member] | Employee Severance [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	5
Severance, asset impairment and other restructuring charges		16
2014 Plan [Member] | Employee Severance [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0
Severance, asset impairment and other restructuring charges		9
2014 Plan [Member] | Employee Severance [Member] | MENA/ Asia Pacific [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	1
Severance, asset impairment and other restructuring charges		4
2014 Plan [Member] | Employee Severance [Member] | Europe/ SSA/ Russia [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0
Severance, asset impairment and other restructuring charges		15
2014 Plan [Member] | Employee Severance [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0
Severance, asset impairment and other restructuring charges		19
2014 Plan [Member] | Employee Severance [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	1
Severance, asset impairment and other restructuring charges		47
2014 Plan [Member] | Employee Severance [Member] | Land Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0
Severance, asset impairment and other restructuring charges		3
2015 Plan [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	41
2015 Plan [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	3
2015 Plan [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	8
2015 Plan [Member] | MENA/ Asia Pacific [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	6
2015 Plan [Member] | Europe/ SSA/ Russia [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	7
2015 Plan [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	12
2015 Plan [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	33
2015 Plan [Member] | Land Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	5
2015 Plan [Member] | One-time Termination Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	33		53
Severance, asset impairment and other restructuring charges	40
2015 Plan [Member] | One-time Termination Benefits [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	3
2015 Plan [Member] | One-time Termination Benefits [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	8
2015 Plan [Member] | One-time Termination Benefits [Member] | MENA/ Asia Pacific [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	5
2015 Plan [Member] | One-time Termination Benefits [Member] | Europe/ SSA/ Russia [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	7
2015 Plan [Member] | One-time Termination Benefits [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	12
2015 Plan [Member] | One-time Termination Benefits [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	32
2015 Plan [Member] | One-time Termination Benefits [Member] | Land Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Severance, asset impairment and other restructuring charges	5
2015 Plan [Member] | Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	1		0
Severance, asset impairment and other restructuring charges	1
2015 Plan [Member] | Other Restructuring [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0
Severance, asset impairment and other restructuring charges	0
2015 Plan [Member] | Other Restructuring [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0
Severance, asset impairment and other restructuring charges	0
2015 Plan [Member] | Other Restructuring [Member] | MENA/ Asia Pacific [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	1
Severance, asset impairment and other restructuring charges	1
2015 Plan [Member] | Other Restructuring [Member] | Europe/ SSA/ Russia [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0
Severance, asset impairment and other restructuring charges	0
2015 Plan [Member] | Other Restructuring [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0
Severance, asset impairment and other restructuring charges	0
2015 Plan [Member] | Other Restructuring [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	1
Severance, asset impairment and other restructuring charges	1
2015 Plan [Member] | Other Restructuring [Member] | Land Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0
Severance, asset impairment and other restructuring charges	0
2015 Plan [Member] | Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	33
2015 Plan [Member] | Employee Severance [Member] | Corporate and Research and Development [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	0
2015 Plan [Member] | Employee Severance [Member] | North America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	16
2015 Plan [Member] | Employee Severance [Member] | MENA/ Asia Pacific [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	6
2015 Plan [Member] | Employee Severance [Member] | Europe/ SSA/ Russia [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	7
2015 Plan [Member] | Employee Severance [Member] | Latin America [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	3
2015 Plan [Member] | Employee Severance [Member] | Core Regional Segments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	32
2015 Plan [Member] | Employee Severance [Member] | Land Drilling Rigs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 1