Summary of Significant Accounting Policies - Schedule Of Other Assets (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	May 31, 2011
Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract]
Deferred financing costs	$ 0	$ 3,111	$ 1,000
Long-term VAT receivable	0	3,440
Long-term prepaid expenses	139	328
Gabon PSC - blocked payment (net to our 66.667% interest)	734	734		700
Other assets	$ 873	$ 7,613