Oil and Gas Properties - Schedule of Unproved Properties (Detail) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Unproven properties	$ 2,701,182	$ 2,196,157
Bulgaria [Member]
Costs Incurred, Oil and Gas Property Acquisition, Exploration, and Development Activities [Line Items]
Unproven properties	$ 2,701,182	$ 2,196,157

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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