Litigation (Details) (USD $)	36 Months Ended		0 Months Ended		1 Months Ended		6 Months Ended							0 Months Ended
	Dec. 31, 1993 breach	Jun. 30, 2014 MTBE [Member] Pending Litigation [Member] LegalMatter	Aug. 03, 2012 Ecuador [Member] Pending Litigation [Member]	Feb. 14, 2011 Ecuador [Member] Pending Litigation [Member]	Sep. 30, 2010 Ecuador [Member] Pending Litigation [Member]	Aug. 31, 2010 Ecuador [Member] Pending Litigation [Member]	Jun. 30, 2014 Ecuador [Member] Pending Litigation [Member] LegalMatter	Nov. 13, 2013 Ecuador [Member] Pending Litigation [Member]	Nov. 06, 2012 Ecuador [Member] Pending Litigation [Member]	Jan. 03, 2012 Ecuador [Member] Pending Litigation [Member]	Feb. 14, 2011 Ecuador [Member] Pending Litigation [Member]	Dec. 31, 2008 Ecuador [Member] Pending Litigation [Member]	Jun. 30, 2014 Pending Litigation [Member] Ecuador [Member]	Jul. 02, 2013 Embargo Order [Member] Ecuador [Member]	Jun. 30, 2014 Declatory Relief Claim [Member] Ecuador [Member] Pending Litigation [Member] LegalMatter	Jun. 30, 2014 Discovery Stay On Claims [Member] Ecuador [Member] Pending Litigation [Member] LegalMatter
Loss Contingencies [Line Items]
Pending lawsuits and claims (in number of claims)		12					9								1	8
Conducted remediation program (in years)							3 years
Remediation program													$ 40,000,000
Financial compensation for purported damages on mining engineer's report												18,900,000,000
Assessment for purported unjust enrichment on mining engineer's report												8,400,000,000
Court order requiring the parties to provide their positions on damages within (in days)						45 days
Approximate damages on plaintiffs' submission, Minimum					16,000,000,000
Approximate damages on plaintiffs' submission, Maximum					76,000,000,000
Approximate unjust enrichment on plaintiffs' submission, Minimum					5,000,000,000
Approximate unjust enrichment on plaintiffs' submission, Maximum					38,000,000,000
Amount assessed in damages								9,500,000,000			8,600,000,000
Amount assessed for plaintiffs representatives											900,000,000
Additional amount assessed in punitive damages											8,600,000,000
Public apology date within judgment/clarification ruling (in days)				15 days
Proposed additional payment for plaintiff attorney fees as percentage of judgment										0.10%
Litigation settlement, amount			$ 19,100,000,000											$ 96,000,000
Number of contract breaches	7
Percentage of payments withheld by third parties due to freeze order									40.00%
Percentage of funds wIthheld by banks due to freeze order									40.00%