Condensed Schedule of Investments (Parenthetical) - USD ($)	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017
Collateral Amount On Open Futures Contracts		$ 4,977,569
United States \| U.S. Treasury Bills 1.56%, 7/05/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	1.56%
Expiration date	7/05/2018
United States \| U.S. Treasury Bills 1.56%, 7/12/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	1.56%
Expiration date	7/12/2018
United States \| U.S. Treasury Bills 1.60%, 7/19/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	1.60%
Expiration date	7/19/2018
United States \| U.S. Treasury Bills 1.61%, 7/26/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	1.61%
Expiration date	7/26/2018
United States \| U.S. Treasury Bills 1.63%, 8/02/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	1.63%
Expiration date	8/02/2018
United States \| U.S. Treasury Bills 1.71%, 8/09/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	1.71%
Expiration date	8/09/2018
United States \| U.S. Treasury Bills 1.77%, 8/16/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	1.77%
Expiration date	8/16/2018
United States \| U.S. Treasury Bills 1.82%, 8/23/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	1.82%
Expiration date	8/23/2018
United States \| U.S. Treasury Bills 1.82%, 8/30/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	1.82%
Expiration date	8/30/2018
United States \| U.S. Treasury Bills 1.85%, 9/06/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	1.85%
Expiration date	9/06/2018
United States \| U.S. Treasury Bills 1.90%, 9/13/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	1.90%
Expiration date	9/13/2018
United States \| U.S. Treasury Bills 1.92%, 9/20/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	1.92%
Expiration date	9/20/2018
United States \| U.S. Treasury Bills 1.90%, 9/27/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	1.90%
Expiration date	9/27/2018
United States \| U.S. Treasury Bills 1.87%, 10/04/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	1.87%
Expiration date	10/04/2018
United States \| U.S. Treasury Bills 1.90%, 10/11/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	1.90%
Expiration date	10/11/2018
United States \| U.S. Treasury Bills 1.97%, 10/18/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	1.97%
Expiration date	10/18/2018
United States \| U.S. Treasury Bills 2.00%, 10/25/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	2.00%
Expiration date	10/25/2018
United States \| U.S. Treasury Bills 2.00%, 11/01/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	2.00%
Expiration date	11/01/2018
United States \| U.S. Treasury Bills 2.03%, 11/08/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	2.03%
Expiration date	11/08/2018
United States \| U.S. Treasury Bills 2.05%, 11/15/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	2.05%
Expiration date	11/15/2018
United States \| U.S. Treasury Bills 2.07%, 11/23/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	2.07%
Expiration date	11/23/2018
United States \| U.S. Treasury Bills 2.05%, 11/29/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	2.05%
Expiration date	11/29/2018
United States \| U.S.Treasury Bills 2.09%, 12/06/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	2.09%
Expiration date	12/06/2018
United States \| U.S.Treasury Bills 2.06%, 12/13/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	2.06%
Expiration date	12/13/2018
United States \| U.S.Treasury Bills 2.09%, 12/20/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	2.09%
Expiration date	12/20/2018
United States \| U.S.Treasury Bills 2.07%, 12/27/2018 \| US Treasury Securities \| Cash Equivalents
Interest rate	2.07%
Expiration date	12/27/2018