Capitalized Exploratory Well Costs (Details 2) (USD $) In Millions, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	$ 1,090		$ 733	$ 545
Suspended Since 2012 and 2013
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	630
Suspended Since 2010 and 2011
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	304
Suspended Since 2009 and Prior
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	156
Northeast Nevada Onshore US [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	23
Northeast Nevada Onshore US [Member] | Suspended Since 2012 and 2013
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	23
Northeast Nevada Onshore US [Member] | Suspended Since 2010 and 2011
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	0
Northeast Nevada Onshore US [Member] | Suspended Since 2009 and Prior
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	0
Troubadour Deepwater Gulf of Mexico [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	47
Troubadour Deepwater Gulf of Mexico [Member] | Suspended Since 2012 and 2013
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	47
Troubadour Deepwater Gulf of Mexico [Member] | Suspended Since 2010 and 2011
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	0
Troubadour Deepwater Gulf of Mexico [Member] | Suspended Since 2009 and Prior
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	0
Diega Offshore Equatorial Guinea [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	216
Diega Offshore Equatorial Guinea [Member] | Suspended Since 2012 and 2013
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	111
Diega Offshore Equatorial Guinea [Member] | Suspended Since 2010 and 2011
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	52
Diega Offshore Equatorial Guinea [Member] | Suspended Since 2009 and Prior
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	53
Carla Offshore Equatorial Guinea [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	149
Carla Offshore Equatorial Guinea [Member] | Suspended Since 2012 and 2013
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	137
Carla Offshore Equatorial Guinea [Member] | Suspended Since 2010 and 2011
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	12
Carla Offshore Equatorial Guinea [Member] | Suspended Since 2009 and Prior
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	0
Felicita Offshore Equatorial Guinea [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	39
Felicita Offshore Equatorial Guinea [Member] | Suspended Since 2012 and 2013
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	4
Felicita Offshore Equatorial Guinea [Member] | Suspended Since 2010 and 2011
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	6
Felicita Offshore Equatorial Guinea [Member] | Suspended Since 2009 and Prior
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	29
Yolanda Offshore Equatorial Guinea [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	20
Yolanda Offshore Equatorial Guinea [Member] | Suspended Since 2012 and 2013
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	3
Yolanda Offshore Equatorial Guinea [Member] | Suspended Since 2010 and 2011
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	3
Yolanda Offshore Equatorial Guinea [Member] | Suspended Since 2009 and Prior
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	14
YoYo Offshore Cameron [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	47
YoYo Offshore Cameron [Member] | Suspended Since 2012 and 2013
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	4
YoYo Offshore Cameron [Member] | Suspended Since 2010 and 2011
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	9
YoYo Offshore Cameron [Member] | Suspended Since 2009 and Prior
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	34
Leviathan [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	181	[1]
Leviathan [Member] | Suspended Since 2012 and 2013
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	71	[1]
Leviathan [Member] | Suspended Since 2010 and 2011
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	110	[1]
Leviathan [Member] | Suspended Since 2009 and Prior
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	0	[1]
Leviathan-1 Deep Offshore Israel [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	78	[1]
Leviathan-1 Deep Offshore Israel [Member] | Suspended Since 2012 and 2013
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	51	[1]
Leviathan-1 Deep Offshore Israel [Member] | Suspended Since 2010 and 2011
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	27	[1]
Leviathan-1 Deep Offshore Israel [Member] | Suspended Since 2009 and Prior
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	0	[1]
Dalit Israel [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	26	[1]
Dalit Israel [Member] | Suspended Since 2012 and 2013
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	4	[1]
Dalit Israel [Member] | Suspended Since 2010 and 2011
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	2	[1]
Dalit Israel [Member] | Suspended Since 2009 and Prior
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	20	[1]
Dolphin 1 Offshore Israel [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	25	[1]
Dolphin 1 Offshore Israel [Member] | Suspended Since 2012 and 2013
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	3	[1]
Dolphin 1 Offshore Israel [Member] | Suspended Since 2010 and 2011
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	22	[1]
Dolphin 1 Offshore Israel [Member] | Suspended Since 2009 and Prior
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	0	[1]
Cyprus A-1 Offshore Cyprus [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	196
Cyprus A-1 Offshore Cyprus [Member] | Suspended Since 2012 and 2013
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	139
Cyprus A-1 Offshore Cyprus [Member] | Suspended Since 2010 and 2011
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	57
Cyprus A-1 Offshore Cyprus [Member] | Suspended Since 2009 and Prior
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	0
Other Projects [Member]
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	43
Other Projects [Member] | Suspended Since 2012 and 2013
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	33
Other Projects [Member] | Suspended Since 2010 and 2011
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	4
Other Projects [Member] | Suspended Since 2009 and Prior
Projects with Exploratory Well Costs Capitalized for More than One Year [Line Items]
Capitalized Exploratory Well Costs that Have Been Capitalized for Period Greater than One Year	$ 6

[1] In March 2014, we and our partners reached an agreement with the Israel Antitrust Authority on various matters (Consent Decree). The Consent Decree, which was subject to final approval by the Antitrust Tribunal, granted the rights, to us and our partners, to jointly market natural gas from the Leviathan field. Also as a result of the Consent Decree, we agreed to divest our Tanin and Karish natural gas discoveries. However, on December 23, 2014, we and our partners in the Leviathan field were advised by the Israel Antitrust Authority of its decision to not submit the Consent Decree to the Antitrust Tribunal for final approval. This is a matter that we believed was resolved some time ago and we had received recent assurances from the Antitrust Authority that approval was forthcoming. We requested an oral hearing with the Antitrust Authority, which took place on January 27, 2015, and await final disposition.