Litigation (Details) $ in Millions			1 Months Ended		12 Months Ended
	Aug. 03, 2012 USD ($)	Feb. 14, 2011 USD ($)	Sep. 30, 2010 USD ($)	Aug. 31, 2010	Dec. 31, 2015 LegalMatter breach	Dec. 31, 1998 USD ($)	Nov. 13, 2013 USD ($)	Jul. 02, 2013 USD ($)	Nov. 06, 2012	Jan. 03, 2012	Dec. 31, 2008 USD ($)
Loss Contingencies [Line Items]
Number of contract breaches | breach					7
MTBE [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Pending lawsuits and claims (in number of claims) | LegalMatter					7
Ecuador Litigation [Member]
Loss Contingencies [Line Items]
Pending lawsuits and claims (in number of claims) | LegalMatter					9
Remediation program term (in years)					3 years
Ecuador Litigation [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Remediation program term (in years)						3 years
Remediation program						$ 40
Financial compensation for purported damages on mining engineer's report											$ 18,900
Assessment for purported unjust enrichment on mining engineer's report											$ 8,400
Court order requiring the parties to provide their positions on damages within (in days)				45 days
Range of possible loss, minimum			$ 16,000
Range of possible loss, maximum			76,000
Approximate unjust enrichment on plaintiffs' submission, Maximum			38,000
Approximate unjust enrichment on plaintiffs' submission, Minimum			$ 5,000
Amount assessed in damages		$ 8,600					$ 9,500
Amount assessed for plaintiffs representatives		900
Additional amount assessed in punitive damages		$ 8,600
Public apology date within judgment		15 days
Approved court-appointed liquadator's report damages for total judgment	$ 19,100
Litigation Settlement, Amount to be Paid Via Third Party								$ 96
Proposed additional payment for plaintiff attorney fees as percentage of judgment										0.10%
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%
Ecuador Litigation [Member] | Declatory Relief Claim [Member]
Loss Contingencies [Line Items]
Pending lawsuits and claims (in number of claims) | LegalMatter					1
Ecuador Litigation [Member] | Discovery Stay On Claims [Member]
Loss Contingencies [Line Items]
Pending lawsuits and claims (in number of claims) | LegalMatter					8