Operating Segments - Operating Segment Assets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
TOTAL ASSETS	$ 734,880	$ 596,837
Operating Segments [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	734,851	596,524
Operating Segments [Member] | Venezuela [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	500,946	428,992
Operating Segments [Member] | Gabon [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	107,851	80,908
Operating Segments [Member] | Indonesia [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	5,004	9,587
Operating Segments [Member] | United States [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	121,050	77,037
Discontinued operations [Member]
Segment Reporting Information [Line Items]
TOTAL ASSETS	$ 29	$ 313