Trading Activities - Offsetting of Derivative Assets and Liabilities (Detail) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Derivative [Line Items]
Gross Amounts Recognized, Assets	$ 1,683,026	$ 2,079,754
Gross Amounts Offset in the Statements of Financial Condition, Assets	(1,032,826)	(1,745,551)
Amounts Presented in the Statements of Financial Condition, Assets	650,200	334,203
Net Amount, Assets	650,200	334,203
Gross Amounts Recognized, Liabilities	(1,294,215)	(1,754,621)
Gross Amounts Offset in the Statements of Financial Condition, Liabilities	1,032,826	1,745,551
Amounts Presented in the Statements of Financial Condition, Liabilities	(261,389)	(9,070)
Gross Amounts Not Offset in the Statements of Financial Condition, Cash Collateral Received/ Pledged, Liabilities	261,389	9,070
Net fair value	650,200	334,203
Futures Contracts [Member]
Derivative [Line Items]
Gross Amounts Recognized, Assets	1,455,308	1,456,716
Gross Amounts Offset in the Statements of Financial Condition, Assets	(805,108)	(1,122,513)
Amounts Presented in the Statements of Financial Condition, Assets	650,200	334,203
Net Amount, Assets	650,200	334,203
Gross Amounts Recognized, Liabilities	(805,108)	(1,122,513)
Gross Amounts Offset in the Statements of Financial Condition, Liabilities	805,108	1,122,513
Amounts Presented in the Statements of Financial Condition, Liabilities	0
Forward Contracts [Member]
Derivative [Line Items]
Gross Amounts Recognized, Assets	227,718	623,038
Gross Amounts Offset in the Statements of Financial Condition, Assets	(227,718)	(623,038)
Amounts Presented in the Statements of Financial Condition, Assets	0
Net Amount, Assets	0
Gross Amounts Recognized, Liabilities	(489,107)	(632,108)
Gross Amounts Offset in the Statements of Financial Condition, Liabilities	227,718	623,038
Amounts Presented in the Statements of Financial Condition, Liabilities	(261,389)	(9,070)
Gross Amounts Not Offset in the Statements of Financial Condition, Cash Collateral Received/ Pledged, Liabilities	$ 261,389	$ 9,070