Trading Activities - Summary of Valuation of Investments (Detail)	Dec. 31, 2018 USD ($)
Derivative [Line Items]
Gross Amounts Recognized, Assets	$ 8,783,398
Gross Amounts Offset in the Statements of Financial Condition, Assets	(7,025,887)
Net Amounts Presented in the Statements of Financial Condition, Assets	1,757,511
Financial Instruments, Assets	0
Collateral Received/Pledged, Assets	0
Net Amount, Assets	1,757,511
Gross Amounts Recognized, Liabilities	(7,390,004)
Gross Amounts Offset in the Statements of Financial Condition, Liabilities	7,025,887
Net Amounts Presented in the Statements of Financial Condition, Liabilities	(364,117)
Financial Instruments, Liabilities	0
Collateral Received/Pledged, Liabilities	0
Net Amount, Liabilities	(364,117)
Net fair value	1,393,394
Futures [Member]
Derivative [Line Items]
Gross Amounts Recognized, Assets	6,579,887
Gross Amounts Offset in the Statements of Financial Condition, Assets	(4,822,376)
Net Amounts Presented in the Statements of Financial Condition, Assets	1,757,511
Financial Instruments, Assets	0
Collateral Received/Pledged, Assets	0
Net Amount, Assets	1,757,511
Gross Amounts Recognized, Liabilities	(4,822,376)
Gross Amounts Offset in the Statements of Financial Condition, Liabilities	4,822,376
Financial Instruments, Liabilities	0
Collateral Received/Pledged, Liabilities	0
Forwards [Member]
Derivative [Line Items]
Gross Amounts Recognized, Assets	2,203,511
Gross Amounts Offset in the Statements of Financial Condition, Assets	(2,203,511)
Financial Instruments, Assets	0
Collateral Received/Pledged, Assets	0
Gross Amounts Recognized, Liabilities	(2,567,628)
Gross Amounts Offset in the Statements of Financial Condition, Liabilities	2,203,511
Net Amounts Presented in the Statements of Financial Condition, Liabilities	(364,117)
Financial Instruments, Liabilities	0
Collateral Received/Pledged, Liabilities	0
Net Amount, Liabilities	$ (364,117)