XML 70 R54.htm IDEA: XBRL DOCUMENT v3.3.1.900
Financial Instruments - Effect of Derivative Instruments on Consolidated Statements of Operations (Parenthetical) (Detail) - USD ($)
$ in Thousands
1 Months Ended 12 Months Ended
Sep. 30, 2014
Jan. 31, 2014
Dec. 31, 2015
Dec. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]        
Gains on settlement of derivative instruments       $ 979
Natural Gas Commodity Contracts [Member]        
Derivative Instruments, Gain (Loss) [Line Items]        
Swaps, settlement dates description     January 2015 through December 2015  
Net proceeds from derivative instruments   $ 276    
Crude Oil Commodity Contracts [Member]        
Derivative Instruments, Gain (Loss) [Line Items]        
Swaps, settlement dates description     January 2016 through December 2016  
Net proceeds from derivative instruments $ 703