Derivative Instruments - Summary of Gross and Net Amounts of Offsetting Assets and Liabilities (Detail) - Morgan Stanley & Co. LLC [Member] - Commodity Futures Contract [Member] - USD ($)	Jun. 30, 2017	Dec. 31, 2016
Offsetting Assets And Liabilities [Line Items]
Financial Derivative Assets	$ 1,764,960	$ 1,242,211
Financial Derivative Liabilities	(1,798,035)	(1,599,451)
Net value of derivatives, Liabilities	(33,075)	(357,240)
Collateral (Received)/Pledged, Non-Cash	$ 33,075	$ 357,240