Annual report pursuant to Section 13 and 15(d)

Supplemental Information on Oil and Natural Gas Properties (unaudited) (Proved Undeveloped Reserves) (Narrative) (Details)

v3.6.0.2
Supplemental Information on Oil and Natural Gas Properties (unaudited) (Proved Undeveloped Reserves) (Narrative) (Details)
$ in Thousands
 2 Months Ended 12 Months Ended
Feb. 22, 2017
item
Dec. 31, 2016
USD ($)
item
MBoe
$ / Boe
Dec. 31, 2015
USD ($)
item
MBoe
$ / Boe
Dec. 31, 2014
USD ($)
item
MBoe
$ / Boe
Dec. 31, 2013
MBoe
Reserve Quantities [Line Items]          
Depletion expense per physical unit of production | $ / Boe   12.81 19.74 27.51  
Lease operating expense per physical unit of production | $ / Boe   6.88 7.71 10.85  
Proved Developed and Undeveloped Reserve, Net (Energy)   91,580 54,271 32,824 14,857
Proved Developed and Proved Undeveloped Reserves, percentage change between periods   69.00% 65.00% 121.00%  
Period to convert the PUDs into proved developed reserves   5 years      
Proved undeveloped reserves, percentage change between periods   88.00% 75.00% 98.00%  
Proved undeveloped reserves   48,348 25,654 14,623 7,387
Proved undeveloped reserves reclassification to proved developed production   6,823      
Proved undeveloped reserves conversion to proved developed reserves, percentage transferred   27.00%   24.00%  
Permian Basin [Member]          
Reserve Quantities [Line Items]          
Proved developed and undeveloped reserve period increase (Decrease)   48,477      
Number of wells drilled during the period | item   29 36 34  
Number of wells drilled during the period, net | item   20.9 27.1 28.7  
Proved undeveloped reserves reclassification to proved developed production     2,742 1,757  
Proved undeveloped reserves conversion to proved developed reserves, percentage transferred     19.00%    
Proved undeveloped reserves conversion to proved developed reserves total cost | $   $ 43,415 $ 55,933 $ 34,619  
Proved undeveloped reserves sales of minerals in place       1,132  
Permian Basin [Member] | Divestitures, 2016 Production And Price Revisions [Member]          
Reserve Quantities [Line Items]          
Proved developed and undeveloped reserve period increase (Decrease)   (11,168)      
Permian Basin [Member] | Continued Horizontal Development [Member]          
Reserve Quantities [Line Items]          
Proved undeveloped reserves extensions discoveries and additions       10,125  
Permian Basin [Member] | Proved Undeveloped Reserves [Member] | Continued Horizontal Development [Member]          
Reserve Quantities [Line Items]          
Proved developed and undeveloped reserve period increase (Decrease)   12,035 13,774    
Permian Basin [Member] | Proved Undeveloped Reserves [Member] | Acquisitions Net of Divestitures [Member]          
Reserve Quantities [Line Items]          
Proved developed and undeveloped reserve period increase (Decrease)   17,482      
Subsequent Event [Member]          
Reserve Quantities [Line Items]          
Number of horizontal wells drilled gross | item 4        
Number of horizontal wells drilled net | item 3.4        
Number of completed horizontal wells gross | item 5        
Number of completed horizontal wells net | item 3.4        
Number of horizontal wells in progress gross | item 5        
Number of horizontal wells in progress net | item 4.1