Commitments and Contingencies - Additional Information (Detail)	0 Months Ended	1 Months Ended	12 Months Ended				1 Months Ended				12 Months Ended	0 Months Ended	1 Months Ended			12 Months Ended
	Jul. 24, 2013 USD ($) Plaintiff	May 31, 2011 USD ($)	Dec. 31, 2013 USD ($) Person	Dec. 31, 2013 IDR	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Mar. 31, 2007 Uracoa Municipality Tax Assessments [Member] Claim	Aug. 31, 2006 Uracoa Municipality Tax Assessments [Member] Claim	Jul. 31, 2006 Uracoa Municipality Tax Assessments [Member] Claim	Jul. 31, 2004 Uracoa Municipality Tax Assessments [Member] Claim	Dec. 31, 2013 Uracoa Municipality Tax Assessments [Member] Assessment	May 04, 2012 Libertador Municipality Tax Assessments [Member] Claim	Jul. 31, 2007 Libertador Municipality Tax Assessments [Member] Claim	Jun. 30, 2007 Libertador Municipality Tax Assessments [Member] Claim	Apr. 30, 2005 Libertador Municipality Tax Assessments [Member] Claim	Dec. 31, 2013 Libertador Municipality Tax Assessments [Member] Assessment	Dec. 31, 2013 Farmout Agreements [Member] USD ($)
Legal Contingencies [Line Items]
Number of executive officers under employment contacts			5	5
Notice period for terminating employment contract			1 year	1 year
Termination date of employment contracts			May 31, 2013	May 31, 2013
Period of initial exploration phase			6 years	6 years
Date granted for extended period of initial exploration phase			Jan. 15, 2017	Jan. 15, 2017
Extended period of initial exploration phase			4 years	4 years
Percentage of expected amount to pay partner			7.10%	7.10%
Expected amount to pay partner			$ 3,200,000
Complaint alleged damages amount	2,900,000
Number of Plaintiffs	70
Compensation claim for land local currency				16,000,000,000
Compensation claim for land USD value at cost			1,700,000
Compensation claim for land USD value net to cost sharing interest			1,200,000
Percentage of cost sharing interest in work commitments			71.61%	71.61%
Purchased land value, at cost			4,100
Blocked payment at cost		1,100,000
Blocked payment net to cost sharing interest		700,000	734,000		734,000
Date of OFAC application for return of blocked funds			Oct. 26, 2011	Oct. 26, 2011
Cost sharing interest		66.667%	66.667%	66.667%	66.667%
Number of tax assessments											9					5
Number of claim filed							2	2	2	3			2	2	1
Number of claim dismissed												1
Impairment charge			575,000		2,900,000	3,335,000											3,200,000
Accrual of impairment charge																	$ 2,000,000