Annual report pursuant to Section 13 and 15(d)

Fair Value of Derivative Instruments on Condensed Consolidated Balance Sheets (Detail)

v3.20.4
Fair Value of Derivative Instruments on Condensed Consolidated Balance Sheets (Detail) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Derivatives, Fair Value [Line Items]      
Derivatives $ 88,422,000 $ (68,131,000) $ 37,427,000
Commodity derivative assets – current 78,793,000 4,131,000  
Derivative assets, noncurrent 25,449,000 2,750,000  
Derivative liabilities, noncurrent 28,434,000 3,385,000  
Derivative Asset 104,242,000 6,881,000  
Derivative liabilities, current 85,427,000 23,450,000  
Derivative liabilities 113,861,000 26,835,000  
Commodity contracts      
Derivatives, Fair Value [Line Items]      
Derivative Asset 4,300,000    
Commodity contracts | Derivative assets/liabilities - current      
Derivatives, Fair Value [Line Items]      
Commodity derivative assets – current 78,793,000 4,131,000  
Derivative liabilities, current 81,772,000 23,450,000  
Commodity contracts | Derivative assets/liabilities - noncurrent      
Derivatives, Fair Value [Line Items]      
Derivative assets, noncurrent 25,449,000 2,750,000  
Derivative liabilities, noncurrent 26,789,000 3,385,000  
Interest Rate Swap | Derivative assets/liabilities - current      
Derivatives, Fair Value [Line Items]      
Commodity derivative assets – current 0 0  
Derivative liabilities, current 3,655,000 0  
Interest Rate Swap | Derivative assets/liabilities - noncurrent      
Derivatives, Fair Value [Line Items]      
Derivative assets, noncurrent 0 0  
Derivative liabilities, noncurrent 1,645,000 0  
Fair Value, Measurements, Recurring | Commodity contracts      
Derivatives, Fair Value [Line Items]      
Commodity derivative assets – current 78,793,000 4,131,000  
Derivative assets, noncurrent 25,449,000 2,750,000  
Derivative liabilities, noncurrent 26,789,000 3,385,000  
Derivative liabilities, current (81,772,000) $ (23,450,000)  
Fair Value, Measurements, Recurring | Interest Rate Swap      
Derivatives, Fair Value [Line Items]      
Derivative liabilities, noncurrent 1,645,000    
Derivative liabilities, current $ (3,655,000)