Quarterly report pursuant to Section 13 or 15(d)

Property and Equipment, Net (Narrative) (Details)

v3.20.2
Property and Equipment, Net (Narrative) (Details)
 3 Months Ended 9 Months Ended
Dec. 31, 2020
$ / bbl
Sep. 30, 2020
USD ($)
$ / bbl
Mar. 31, 2020
USD ($)
Sep. 30, 2019
USD ($)
$ / bbl
Mar. 31, 2019
USD ($)
Sep. 30, 2020
USD ($)
$ / bbl
Sep. 30, 2019
USD ($)
$ / bbl
Property, Plant and Equipment [Abstract]              
Internal costs capitalized   $ 10,300,000   $ 8,200,000   $ 26,700,000 $ 27,400,000
Interest costs capitalized   20,700,000   18,100,000   65,600,000 56,700,000
Amount transferred from unevaluated properties into evaluated properties           235,900,000  
Impairment of evaluated oil and gas properties   $ 684,956,000 $ 0 $ 0 $ 0 $ 1,961,474,000 $ 0
Property, Plant and Equipment [Line Items]              
Beginning of period 12-Month Average Realized Price ($/Bbl) | $ / bbl   45.87   53.00   53.90 58.40
Forecast              
Property, Plant and Equipment [Line Items]              
Beginning of period 12-Month Average Realized Price ($/Bbl) | $ / bbl 39.65