Related Party Transactions - Schedule of Net Assets Recorded by Partnership (Detail) (USD $)
In Thousands, unless otherwise specified
Dec. 31, 2014
Dec. 31, 2013
Apr. 01, 2014
Oct. 01, 2014
Mar. 28, 2013
Oct. 01, 2013
Apr. 02, 2012
May 14, 2012
Dec. 12, 2012
Related Party Transaction [Line Items]                  
Noncontrolling interest $ (5,560) $ (5,528)              
Double A Acquisition [Member]                  
Related Party Transaction [Line Items]                  
Oil and natural gas properties, net     37,838            
Asset retirement obligations     (908)            
Other current liabilities     (722)            
Total identifiable net assets     36,208            
Wattenberg Acquisition [Member]                  
Related Party Transaction [Line Items]                  
Oil and natural gas properties, net       9,822          
Asset retirement obligations       (149)          
Total identifiable net assets       9,673          
WHT Acquisition [Member]                  
Related Party Transaction [Line Items]                  
Oil and natural gas properties, net         192,280        
Asset retirement obligations         (2,753)        
Total identifiable net assets         106,674        
Cash and cash equivalents         1,354        
Accounts receivable         3,866        
Short-term derivative instruments, net         1,206        
Prepaid expenses and other current assets         98        
Long-term derivative instruments, net         3,528        
Accrued liabilities         (3,494)        
Credit facilities         (89,300)        
Other long-term liabilities         (111)        
Cinco Group acquisition [Member]                  
Related Party Transaction [Line Items]                  
Oil and natural gas properties, net           457,439      
Asset retirement obligations           (13,575)      
Total identifiable net assets           297,627      
Cash and cash equivalents           3,265      
Accounts receivable           10,615      
Short-term derivative instruments, net           (1,505)      
Prepaid expenses and other current assets           1,824      
Long-term derivative instruments, net           3,056      
Accrued liabilities           (3,311)      
Credit facilities           (151,690)      
Other long-term liabilities           (265)      
Other long-term assets           356      
Accounts payable           (4,063)      
Revenue payable           (4,519)      
Tanos/Classic Properties [Member]                  
Related Party Transaction [Line Items]                  
Oil and natural gas properties, net             15,164    
Asset retirement obligations             (466)    
Total identifiable net assets             16,070    
Short-term derivative instruments, net             715    
Long-term derivative instruments, net             674    
Accrued liabilities             (17)    
East Texas Properties [Member]                  
Related Party Transaction [Line Items]                  
Oil and natural gas properties, net               31,716  
Asset retirement obligations               (43)  
Total identifiable net assets               34,569  
Accounts receivable               612  
Short-term derivative instruments, net               1,017  
Long-term derivative instruments, net               1,337  
Accrued liabilities               (70)  
Beta [Member]                  
Related Party Transaction [Line Items]                  
Oil and natural gas properties, net                 108,342
Asset retirement obligations                 (58,746)
Total identifiable net assets                 93,696
Cash and cash equivalents                 6,021
Accounts receivable                 16,284
Short-term derivative instruments, net                 2,926
Prepaid expenses and other current assets                 4,521
Accrued liabilities                 (9,140)
Credit facilities                 (28,500)
Accounts payable                 (9,092)
Restricted investments                 68,009
Deferred tax liability                 (1,674)
Noncontrolling interest                 $ (5,255)