Annual report pursuant to Section 13 and 15(d)

Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail)

v3.10.0.1
Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($)
$ in Thousands
Dec. 31, 2018
Dec. 31, 2017
Assets:    
Commodity derivative assets – current $ 34,932 $ 0
Derivative assets 10,100 0
Liabilities:    
Derivative liabilities, current 991 27,777
Derivative liabilities, noncurrent 0 (13,900)
Fair Value, Measurements, Recurring | Commodity contracts    
Assets:    
Commodity derivative assets – current 34,932  
Derivative assets 10,100  
Liabilities:    
Derivative liabilities, current (991) (27,777)
Derivative liabilities, noncurrent 0 (13,900)
Fair Value, Measurements, Recurring | Commodity contracts | Level 1    
Assets:    
Commodity derivative assets – current 0  
Derivative assets 0  
Liabilities:    
Derivative liabilities, current 0 0
Derivative liabilities, noncurrent 0 0
Fair Value, Measurements, Recurring | Commodity contracts | Level 2    
Assets:    
Commodity derivative assets – current 34,932  
Derivative assets 10,100  
Liabilities:    
Derivative liabilities, current (991) (27,777)
Derivative liabilities, noncurrent 0 (13,900)
Fair Value, Measurements, Recurring | Commodity contracts | Level 3    
Assets:    
Commodity derivative assets – current 0  
Derivative assets 0  
Liabilities:    
Derivative liabilities, current 0 0
Derivative liabilities, noncurrent $ 0 $ 0