Annual report pursuant to Section 13 and 15(d)

Supplemental Information on Oil and Gas Exploration and Production Activities (Unaudited) - Capitalized Costs Related to Oil and Gas Producing Activities (Details)

v3.20.4
Supplemental Information on Oil and Gas Exploration and Production Activities (Unaudited) - Capitalized Costs Related to Oil and Gas Producing Activities (Details) - USD ($)
$ in Thousands
Dec. 31, 2020
Dec. 31, 2019
Extractive Industries [Abstract]    
Proved properties $ 9,359,866 $ 8,909,069
Unproved properties 1,457,043 1,686,666
Capitalized costs, gross 10,816,909 10,595,735
Accumulated depreciation, depletion, amortization and impairment (8,778,759) (7,191,957)
Net capitalized costs $ 2,038,150 $ 3,403,778