v2.4.0.6
Commitments and Contingencies - Additional Information (Detail) (USD $)
9 Months Ended 10 Months Ended 12 Months Ended
Sep. 30, 2012
Oct. 31, 2012
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Joint venture term 10 years        
Initial capital contribution   $ 10,000,000      
Non-Cancelable operating lease expiration date     2017    
Non-Cancelable lease agreement for office space, expiration date     December 31, 2017    
Rent expense under lease arrangements     716,000 630,000 463,000
Drilling contracts [Member]
         
Commitment under contracts     5,400,000    
Employment agreements [Member]
         
Commitment under contracts     $ 4,900,000