Segment Information (Details) - USD ($) $ in Millions		3 Months Ended			6 Months Ended
		Jun. 30, 2016		Jun. 30, 2015	Jun. 30, 2016		Jun. 30, 2015
Segment Reporting Information [Line Items]
Long-Lived Assets Impairment				$ 124	$ 0		$ 124
Net Operating Revenues		$ 1,402		2,390	2,987		5,184
Operating Income (Loss)		(460)		(464)	(907)		(414)
Depreciation and Amortization		249		311	499		627
Corporate and Research and Development		(41)		(59)	(86)		(123)
Restructuring Charges		(51)		(69)	(128)		(110)
Litigation Charges, Net		114		112	181		112
Gain (Loss) on Disposition of Business		0		(5)	(1)		(2)
Professional Fees				3			5
Other Expenses				2			11
Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Operating Revenues		1,402		2,390	2,987		5,184
Operating Income (Loss)		(66)		36	(223)		265
Depreciation and Amortization		245		305	491		615
Operating Segments [Member] | Core Regional Segments [Member]
Segment Reporting Information [Line Items]
Net Operating Revenues		1,293		2,205	2,759		4,804
Operating Income (Loss)		(49)		32	(180)		251
Depreciation and Amortization		222		278	446		559
Operating Segments [Member] | Drilling Rigs [Member]
Segment Reporting Information [Line Items]
Net Operating Revenues		109		185	228		380
Operating Income (Loss)		(17)		4	(43)		14
Depreciation and Amortization		23		27	45		56
Corporate and Research and Development [Member]
Segment Reporting Information [Line Items]
Depreciation and Amortization		4		6	8		12
Corporate and Research and Development		(75)		(105)	(163)		(225)
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Goodwill, Impairment Loss				(20)			(20)
Impairment of Long-Lived Assets and Other Related Charges		154	[1]	(181)	211	[1]	(191)
Restructuring Charges	[2]	(51)		(69)	(128)		(110)
Litigation Charges, Net		114		(112)	181		(112)
Gain (Loss) on Disposition of Business				(5)	(1)		(2)
Other Items	[3]			(8)			(19)
North America [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Operating Revenues		401		808	944		1,971
Operating Income (Loss)		(101)		(92)	(229)		(102)
Depreciation and Amortization		58		97	112		202
MENA/ Asia Pacific [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Operating Revenues		400		516	761		1,049
Operating Income (Loss)		50		(17)	4		43
Depreciation and Amortization		60		66	121		131
Europe/ SSA/ Russia [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Operating Revenues		243		418	500		835
Operating Income (Loss)		1		65	0		136
Depreciation and Amortization		48		53	96		103
Latin America [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Net Operating Revenues		249		463	554		949
Operating Income (Loss)		1		76	45		174
Depreciation and Amortization		$ 56		62	$ 117		123
2015 Plan [Member]
Segment Reporting Information [Line Items]
Restructuring Charges				(69)			(110)
2015 Plan [Member] | Core Regional Segments [Member]
Segment Reporting Information [Line Items]
Restructuring Charges				(68)			(101)
2015 Plan [Member] | Drilling Rigs [Member]
Segment Reporting Information [Line Items]
Restructuring Charges				(1)			(6)
2015 Plan [Member] | Corporate and Research and Development [Member]
Segment Reporting Information [Line Items]
Restructuring Charges				0			(3)
2015 Plan [Member] | North America [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Restructuring Charges				(21)			(29)
2015 Plan [Member] | MENA/ Asia Pacific [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Restructuring Charges				(29)			(35)
2015 Plan [Member] | Europe/ SSA/ Russia [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Restructuring Charges				(14)			(21)
2015 Plan [Member] | Latin America [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Restructuring Charges				$ (4)			$ (16)

[1] Includes $84 million to adjust a note from PDVSA to fair value and other impairments and write-offs of $70 million.

[2] Includes restructuring charges of $51 million: $15 million in North America, $10 million in Europe/SSA/Russia, $12 million in Latin America, $11 million in MENA/Asia Pacific, $2 million in Corporate and Research and Development, and $1 million in Land Drilling Rigs.

[3] Includes professional fees of $3 million related to the divestiture of non-core businesses, facility closure fees of $3 million, restatement related litigation, post-settlement monitor and auditor expenses and other charges of $2 million.