XML 50 R33.htm IDEA: XBRL DOCUMENT v3.6.0.2
FAIR VALUE OF FINANCIAL INSTRUMENTS (Fair Value of Derivative Instruments) (Detail) - USD ($)
Dec. 31, 2016
Dec. 31, 2015
Commodity Contracts [Member] | Assets [Member] | Future [Member]    
Derivatives Fair Value [Line Items]    
Derivatives not Accounted for as Hedging Instruments $ 111,290,560 $ (138,508,060)