Summary of Significant Accounting Policies - Summary of Gross and Net Amounts of Offsetting Assets and Liabilities (Detail) - Commodity Futures Contract [Member] - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Offsetting Assets And Liabilities [Line Items]
Gross Amounts of Recognized Assets	$ 15,881,662	$ 5,442,464
Gross Amounts Offset Assets in the Statement of Financial Condition	(14,666,572)	(5,416,324)
Net Amounts of Assets Presented in the Statement of Financial Condition	1,215,090	26,140
Assets Net Amount	1,215,090	26,140
Gross Amounts of Recognized Liabilities	(14,666,572)	(5,416,324)
Gross Amounts Offset Liabilities in the Statement of Financial Condition	$ 14,666,572	$ 5,416,324