Derivative Instruments - Summary of Gross and Net Amounts of Offsetting Assets and Liabilities (Detail) - Commodity Currency Contract [Member] - Morgan Stanley & Co. LLC [Member] - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Offsetting Assets And Liabilities [Line Items]
Financial Derivative Assets, Futures Contracts	$ 642,855	$ 134,300
Financial Derivative Liabilities, Futures Contracts	(667,220)
Net value of derivatives, Liabilities	(24,365)
Collateral (Received)/Pledged, Non-Cash	$ 24,365
Net value of derivatives, Assets		134,300
Financial Derivative Assets, Net amount		$ 134,300