v2.4.0.6
Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)
 1 Months Ended 12 Months Ended
Sep. 30, 2012
Dec. 31, 2012
D
Customer
Dec. 31, 2011
Customer
Dec. 31, 2010
Oct. 31, 2012
Summary Of Significant Accounting Policies [Line Items]          
Depreciation depletion and amortization for oil & gas   $ 60,381,000 $ 32,475,000 $ 22,224,000  
Impairment expense for oil & gas     15,200,000    
Estimated fair value of oil and gas property     2,700,000    
Proceeds from sale of working interest     360,000    
Gain on the sale of working interest, net of foreign currency     248,000    
Number of days in which payment is to be made   30      
Number of customers for oil and gas   7 7    
Contract period to sell NGLs and Natural gas production   January 2016      
Crocket County oil supply to joint venture, Period 10 years        
Initial contribution to joint venture-Pipeline and facilities construction         10,000,000
Depreciation expense for other property and equipment   333,000 372,000 233,000  
Tax benefit   50.00%      
Recognized translation loss, net of income tax     20,000 4,000  
Minimum [Member]
          
Summary Of Significant Accounting Policies [Line Items]          
Estimated useful lives of furniture, fixtures and equipment   3 years      
Maximum [Member]
          
Summary Of Significant Accounting Policies [Line Items]          
Estimated useful lives of furniture, fixtures and equipment   10 years      
Oil and Gas [Member] | Minimum [Member]
          
Summary Of Significant Accounting Policies [Line Items]          
Number of days in which payment is to be made   30      
Oil and Gas [Member] | Maximum [Member]
          
Summary Of Significant Accounting Policies [Line Items]          
Number of days in which payment is to be made   60      
Oil Pipeline Joint Venture [Member]
          
Summary Of Significant Accounting Policies [Line Items]          
Equity interest ownership percentage   50.00%      
NGLs (MBbls) [Member]
          
Summary Of Significant Accounting Policies [Line Items]          
Joint venture ownership interest period   10 years      
Boomerang Project [Member]
          
Summary Of Significant Accounting Policies [Line Items]          
Impairment resulted from a write-off       2,600,000  
British Columbia Project [Member]
          
Summary Of Significant Accounting Policies [Line Items]          
Write-off costs in projects       2,600,000  
Unproved properties [Member]
          
Summary Of Significant Accounting Policies [Line Items]          
Impairment expense for oil & gas     $ 3,300,000