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FAIR VALUE OF FINANCIAL INSTRUMENTS (Fair Value of Derivative Instruments) (Details) - USD ($) | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016
Commodity Contracts | Assets | Futures |  |
Derivatives, Fair Value [Line Items] |  |
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net | $ 11,072,567 | $ 17,277,775

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- Definition Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4C -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959 + Details
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