Quarterly report pursuant to Section 13 or 15(d)

Acquisitions (Narrative) (Details)

v3.5.0.2
Acquisitions (Narrative) (Details)
$ in Thousands
Oct. 20, 2016
USD ($)
a
Aug. 03, 2016
USD ($)
May 26, 2016
USD ($)
a
shares
May 16, 2016
USD ($)
a
Jan. 18, 2016
USD ($)
Sep. 30, 2016
USD ($)
Business Acquisition [Line Items]            
Acquisition deposit           $ 32,700
Plymouth Transaction [Member]            
Business Acquisition [Line Items]            
Acquisition deposit           $ 32,700
Howard County, Texas [Member] | Big Star Transaction [Member]            
Business Acquisition [Line Items]            
Consideration transferred     $ 220,000      
Aggregate purchase price     $ 329,573      
Shares of common stock issued in acquisition | shares     9,333,333      
Gas and oil area, developed and undeveloped, gross | a     17,298      
Gas and oil area, developed and undeveloped, net | a     14,089      
Working interest     81.00%      
Net revenue interest     61.00%      
Howard County, Texas [Member] | Plymouth Transaction [Member] | Subsequent Event [Member]            
Business Acquisition [Line Items]            
Consideration transferred $ 340,686          
Gas and oil area, developed and undeveloped, gross | a 6,904          
Gas and oil area, developed and undeveloped, net | a 5,952          
Working interest 82.00%          
Net revenue interest 62.00%          
Casselman-Bohannon Fields [Member]            
Business Acquisition [Line Items]            
Consideration transferred   $ 13,000        
Aggregate purchase price   $ 13,000     $ 10,183  
Working interest   75.30%        
Net revenue interest   58.50%        
Casselman-Bohannon Fields [Member] | Additional Acquisition [Member]            
Business Acquisition [Line Items]            
Consideration transferred         $ 10,183  
Working interest   4.00%     4.90%  
Net revenue interest   3.00%     3.70%  
Western Reagan County, Texas [Member] | AMI Transaction [Member]            
Business Acquisition [Line Items]            
Consideration transferred       $ 33,012    
Aggregate purchase price       $ 33,012    
Western Reagan County, Texas [Member] | AMI Transaction [Member] | TRP Energy, LLC [Member]            
Business Acquisition [Line Items]            
Gas and oil area, developed and undeveloped, net | a       4,745    
Percentage of ownership interest acquired       55.00%    
Sale of ownership interest, percent       27.50%