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Condensed Schedule of Investments (Parenthetical)	6 Months Ended
	Jun. 30, 2018 USD ($)
Collateral Amount On Open Futures Contracts	$ 30,787,364
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.56%, 7/05/2018 [Member]
Interest rate	1.56%
Expiration date	7/05/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.56%, 7/12/2018 [Member]
Interest rate	1.56%
Expiration date	7/12/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.77%, 8/16/2018 [Member]
Interest rate	1.77%
Expiration date	8/16/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.82%, 8/23/2018 [Member]
Interest rate	1.82%
Expiration date	8/23/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.85%, 9/06/2018 [Member]
Interest rate	1.85%
Expiration date	9/06/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.90%, 9/27/2018 [Member]
Interest rate	1.90%
Expiration date	9/27/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.90%, 10/11/2018 [Member]
Interest rate	1.90%
Expiration date	10/11/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 1.97%, 10/18/2018 [Member]
Interest rate	1.97%
Expiration date	10/18/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.00%, 10/25/2018 [Member]
Interest rate	2.00%
Expiration date	10/25/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.00%, 11/01/2018 [Member]
Interest rate	2.00%
Expiration date	11/01/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.03%, 11/08/2018 [Member]
Interest rate	2.03%
Expiration date	11/08/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.05%, 11/15/2018 [Member]
Interest rate	2.05%
Expiration date	11/15/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.07%, 11/23/2018 [Member]
Interest rate	2.07%
Expiration date	11/23/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.05%, 11/29/2018 [Member]
Interest rate	2.05%
Expiration date	11/29/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.09%, 12/06/2018 [Member]
Interest rate	2.09%
Expiration date	12/06/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.06%, 12/13/2018 [Member]
Interest rate	2.06%
Expiration date	12/13/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.09%, 12/20/2018 [Member]
Interest rate	2.09%
Expiration date	12/20/2018
Cash Equivalents [Member] | United States Treasury Obligations [Member] | U.S. Treasury Bills 2.07%, 12/27/2018 [Member]
Interest rate	2.07%
Expiration date	12/27/2018

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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The list of dates or date range within which the options may be exercised of the investment subject to option.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 320
-Section S99
-Paragraph 5
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