Annual report pursuant to Section 13 and 15(d)

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

v3.6.0.2
Fair Value of Derivative Instruments on Condensed Consolidated Balance Sheets (Detail) - USD ($)
$ in Thousands
Dec. 31, 2016
Dec. 31, 2015
Derivatives, Fair Value [Line Items]    
Derivative assets, current $ 0 $ 97,956
Derivative assets 0 97,956
Derivative liabilities, noncurrent 14,437 0
Derivative liabilities, current 12,932 0
Derivative liabilities 27,369 0
Commodity contracts    
Derivatives, Fair Value [Line Items]    
Derivative liabilities 27,400  
Commodity contracts | Derivative assets/liabilities - current    
Derivatives, Fair Value [Line Items]    
Derivative assets, current 0 97,956
Derivative liabilities, current 12,932 0
Commodity contracts | Derivative assets/liabilities - noncurrent    
Derivatives, Fair Value [Line Items]    
Derivative assets, noncurrent 0 0
Derivative liabilities, noncurrent $ 14,437 $ 0