Annual report pursuant to Section 13 and 15(d)

Property and Equipment - Narrative (Details)

v3.20.4
Property and Equipment - Narrative (Details)
12 Months Ended
Dec. 31, 2020
USD ($)
usd_per_mcf
Dec. 31, 2019
USD ($)
usd_per_mcf
Dec. 31, 2018
USD ($)
usd_per_mcf
Property, Plant and Equipment [Line Items]      
Impairment of oil and natural gas properties $ 1,357,099,000 $ 2,039,770,000 $ 0
Capitalized general and administrative costs $ 25,000,000.0 $ 30,100,000 $ 37,700,000
Depletion per Mcf of gas equivalent (usd per Mcfe) | usd_per_mcf 0.61 1.08 0.96
Capitalized costs of oil and natural gas properties excluded from amortization $ 1,457,043,000 $ 1,686,666,000  
Non producing leases extension term 5 years    
Minimum      
Property, Plant and Equipment [Line Items]      
Expected number of years amortization will commence 3 years    
Maximum      
Property, Plant and Equipment [Line Items]      
Expected number of years amortization will commence 5 years