Annual report pursuant to Section 13 and 15(d)

Supplemental Information on Oil and Natural Gas Properties (Unaudited) (Narrative) (Details)

v3.20.4
Supplemental Information on Oil and Natural Gas Properties (Unaudited) (Narrative) (Details)
MMBoe in Thousands, MBoe in Thousands
12 Months Ended
Dec. 31, 2020
MMBoe
MBoe
Dec. 31, 2019
well
MBoe
MMBoe
Dec. 31, 2018
MBoe
MMBoe
Dec. 31, 2017
MBoe
Reserve Quantities [Line Items]        
Proved developed and undeveloped reserve period increase (decrease) (64,100) 301,500 101,500  
Extensions and discoveries | MBoe 41,407 59,424 84,955  
Revisions to previous estimates | MBoe   (37,216) (11,086)  
Decrease in average realized price (percent) (31.00%)      
Number of wells drilled during the period, net | well   57.5    
Proved developed reserves (energy) | MBoe 211,925 230,977 128,605 69,318
Proved undeveloped reserves (energy) | MBoe 263,954 309,035 109,903 67,656
Sale of reserves in place | MBoe 16,120 32,456 0  
Number of wells drilled during the period | well   70    
Production | MBoe (37,193) (15,086) (12,018)  
Purchase of reserves in place | MBoe 0 326,838 39,683  
Computation of proved reserves, discount factor as percent 10.00%      
Price Revisions        
Reserve Quantities [Line Items]        
Revisions to previous estimates (26,200) (5,700)    
Uneconomic Proved Developed Reserves        
Reserve Quantities [Line Items]        
Revisions to previous estimates (2,100)      
Uneconomic Proved Undeveloped Reserves        
Reserve Quantities [Line Items]        
Revisions to previous estimates (800)      
Development Plan Revisions        
Reserve Quantities [Line Items]        
Revisions to previous estimates (24,000) (9,800) (9,100)  
Revisions due to changes in expected recovery timeframe        
Reserve Quantities [Line Items]        
Revisions to previous estimates (24,200)      
Revisions due to NGL separation from Gas        
Reserve Quantities [Line Items]        
Revisions to previous estimates 14,700      
Revisions due to changes in operational expenses        
Reserve Quantities [Line Items]        
Revisions to previous estimates 7,500      
Technical revisions of PUDs        
Reserve Quantities [Line Items]        
Revisions to previous estimates     (2,000)  
Revisions due to well spacing        
Reserve Quantities [Line Items]        
Revisions to previous estimates   (21,700)    
Proved Developed Reserves        
Reserve Quantities [Line Items]        
Extensions and discoveries 11,700   28,200  
Purchase of reserves in place | MBoe     29,800  
Permian Basin        
Reserve Quantities [Line Items]        
Revisions to previous estimates (52,227)