XML 44 R29.htm IDEA: XBRL DOCUMENT v3.10.0.1
FAIR VALUE OF FINANCIAL INSTRUMENTS (Fair Value of Derivative Instruments) (Details) - USD ($)
Jun. 30, 2018
Dec. 31, 2017
Commodity Contracts | Assets | Futures    
Derivatives, Fair Value [Line Items]    
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net $ 16,534,641 $ 11,072,567