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CONTRACTS AND AGREEMENTS (Brokerage Commissions) (Details) - USD ($) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2017 | Sep. 30, 2016 | Sep. 30, 2017 | Sep. 30, 2016
Long Duration Contracts Assumptions By Product And Guarantee [Line Items] |  |  |  |
Brokerage commissions | $ 4,643 | $ 4,869 | $ 13,484 | $ 17,285
Brokerage commissions as a percentage of average daily net assets | 0.02% | 0.02% | 0.02% | 0.02%
Rebalancing Investments Transaction [Member] |  |  |  |
Long Duration Contracts Assumptions By Product And Guarantee [Line Items] |  |  |  |
Brokerage commissions |  |  | $ 10,815 | $ 13,033
Brokerage commissions as a percentage of average daily net assets | 80.21% | 75.40% | 80.21% | 75.40%
Trades Necessitated By Creation And Redemption Activity [Member] |  |  |  |
Long Duration Contracts Assumptions By Product And Guarantee [Line Items] |  |  |  |
Brokerage commissions |  |  | $ 2,669 | $ 4,252
Brokerage commissions as a percentage of average daily net assets | 19.79% | 24.60% | 19.79% | 24.60%

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