Basis of Presentation and Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)
12 Months Ended
Dec. 31, 2013
Segment
Dec. 31, 2012
Dec. 31, 2011
Organization and Summary of Significant Accounting Policies Disclosure [Line Items]      
Senior notes, principal $ 400,000,000 $ 400,000,000  
Senior notes, maturity May 01, 2020    
Number Of Operating Segment 1    
Deferred financing cost 1,900,000 12,300,000 200,000
Deferred financing cost amortization interest expense 2,700,000 1,700,000 1,000,000
Capitalized Interest 15,900,000 4,700,000 1,300,000
Capitalized general and administrative and operating costs 8,400,000 6,000,000 5,200,000
Discount factor 10.00% 10.00% 10.00%
Ceiling test write-down of oil and gas properties 188,000,000    
Restricted cash 18,200,000    
Future Net Revenue from Proved Oil and Gas Reserves
     
Organization and Summary of Significant Accounting Policies Disclosure [Line Items]      
Discount factor 10.00%    
Customer Concentration Risk | Western Refining, Inc.
     
Organization and Summary of Significant Accounting Policies Disclosure [Line Items]      
Concentration of credit risk percentage 61.00% 78.00% 82.00%
Customer Concentration Risk | Plains Marketing LP
     
Organization and Summary of Significant Accounting Policies Disclosure [Line Items]      
Concentration of credit risk percentage 15.00%    
Minimum
     
Organization and Summary of Significant Accounting Policies Disclosure [Line Items]      
Unproved properties, evaluation time for existence of proved reserves 1 year    
Discount factor 7.00%    
Maximum
     
Organization and Summary of Significant Accounting Policies Disclosure [Line Items]      
Unproved properties, evaluation time for existence of proved reserves 3 years    
Discount factor 12.00%    
Office furniture, automobiles, and computer hardware and software | Minimum
     
Organization and Summary of Significant Accounting Policies Disclosure [Line Items]      
Property and equipment estimated useful life 3 years    
Office furniture, automobiles, and computer hardware and software | Maximum
     
Organization and Summary of Significant Accounting Policies Disclosure [Line Items]      
Property and equipment estimated useful life 5 years    
Field offices and partial ownership of aircraft | Minimum
     
Organization and Summary of Significant Accounting Policies Disclosure [Line Items]      
Property and equipment estimated useful life 15 years    
Field offices and partial ownership of aircraft | Maximum
     
Organization and Summary of Significant Accounting Policies Disclosure [Line Items]      
Property and equipment estimated useful life 20 years    
Senior Notes
     
Organization and Summary of Significant Accounting Policies Disclosure [Line Items]      
Senior notes, principal $ 400,000,000