Fair Value Measurements - Summary of Assets and Liabilities Measured at Fair Value (Detail) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Assets
Total assets	$ 3,472,614	$ 1,522,451
Liabilities
Total liabilities	1,283,605	797,089
Futures Contracts [Member]
Assets
Total assets	2,636,639	1,027,835
Liabilities
Total liabilities	664,769	471,939
Forward Contracts [Member]
Assets
Total assets	835,975	494,616
Liabilities
Total liabilities	618,836	325,150
Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) [Member]
Assets
Total assets	2,636,639	1,027,835
Liabilities
Total liabilities	664,769	471,939
Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) [Member] | Futures Contracts [Member]
Assets
Total assets	2,636,639	1,027,835
Liabilities
Total liabilities	664,769	471,939
Significant Other Observable Inputs (Level 2) [Member]
Assets
Total assets	835,975	494,616
Liabilities
Total liabilities	618,836	325,150
Significant Other Observable Inputs (Level 2) [Member] | Forward Contracts [Member]
Assets
Total assets	835,975	494,616
Liabilities
Total liabilities	$ 618,836	$ 325,150