Annual report pursuant to Section 13 and 15(d)

Borrowings (Senior Secured Revolving Credit Facility) (Details)

v3.20.4
Borrowings (Senior Secured Revolving Credit Facility) (Details) - USD ($)
 12 Months Ended
May 07, 2020
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2021
Dec. 20, 2019
Oct. 03, 2016
Line of Credit Facility [Line Items]              
Borrowings outstanding   $ 3,012,641,000 $ 3,185,000,000        
(Gain) loss on extinguishment of debt   (170,370,000) $ 4,881,000 $ 0      
Minimum              
Line of Credit Facility [Line Items]              
Outstanding principal amount of issuance   $ 100,000,000.0         $ 100,000,000.0
6.25% Senior Notes due 2023              
Line of Credit Facility [Line Items]              
Debt instrument, interest rate, stated (as a percent)   6.25%       6.25% 6.25%
6.125% Senior Notes due 2024              
Line of Credit Facility [Line Items]              
Debt instrument, interest rate, stated (as a percent)   6.125%         6.125%
New Credit Facility              
Line of Credit Facility [Line Items]              
Maximum borrowing capacity           $ 5,000,000,000.0  
Current borrowing capacity $ 1,700,000,000 $ 1,600,000,000          
Borrowings outstanding   $ 985,000,000.0          
Interest rate at period end (as a percent)   2.73%          
Letters of credit outstanding   $ 25,200,000          
Reduction in commitments due to issuance   $ 1,600,000,000          
New Credit Facility | Minimum              
Line of Credit Facility [Line Items]              
Unused capacity, commitment fee (as a percent)   0.375%          
New Credit Facility | Maximum              
Line of Credit Facility [Line Items]              
Unused capacity, commitment fee (as a percent)   0.50%          
New Credit Facility | Base Rate | Minimum              
Line of Credit Facility [Line Items]              
Debt instrument interest rate 1.00%            
New Credit Facility | Base Rate | Maximum              
Line of Credit Facility [Line Items]              
Debt instrument interest rate 2.00%            
New Credit Facility | Federal Funds Rate              
Line of Credit Facility [Line Items]              
Debt instrument interest rate   0.50%          
New Credit Facility | LIBOR              
Line of Credit Facility [Line Items]              
Debt instrument interest rate   1.00%          
New Credit Facility | Eurodollar | Minimum              
Line of Credit Facility [Line Items]              
Debt instrument interest rate 2.00%            
New Credit Facility | Eurodollar | Maximum              
Line of Credit Facility [Line Items]              
Debt instrument interest rate 3.00%            
First Amendment to the Credit Agreement | Maximum              
Line of Credit Facility [Line Items]              
Total Funded Debt to EBITDAX Ratio 400.00%            
Leverage ratio 100.00%            
First Amendment to the Credit Agreement | Maximum | Forecast              
Line of Credit Facility [Line Items]              
Total Funded Debt to EBITDAX Ratio         300.00%    
Second Amendment to the Credit Agreement              
Line of Credit Facility [Line Items]              
Current borrowing capacity   $ 1,700,000,000          
Second Lien Notes | Minimum              
Line of Credit Facility [Line Items]              
Outstanding principal amount of issuance   $ 100,000,000.0