Schedules of Investments (Unaudited) - Open S&P GSCI ER Index Futures Contracts (Details)	3 Months Ended	12 Months Ended
Mar. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Number of contracts	36,555	32,510
Expiration date	Jun. 15, 2020	Mar. 16, 2020
Current notional amount	$ 499,758,027	$ 773,217,840
Net unrealized appreciation	$ (125,957,813)	$ 19,634,651

Contract expiration date.

No definition available.

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- Definition

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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- Definition

The number of derivative instruments of a particular group held by the entity.

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- Definition

This element represents the net excess or deficiency of the fair value of an investment (security, contract) over or under its cost (face amount, notional amount), respectively, which excess value or deficiency has not been recognized in earnings of the entity.

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