FAIR VALUE OF FINANCIAL INSTRUMENTS (Fair Value of Derivative Instruments) (Details) - USD ($) |
12 Months Ended | |
|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Commodity Contracts | Assets | Futures | ||
| Derivatives, Fair Value [Line Items] | ||
| Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net | $ 17,277,775 | $ (19,971,629) |