Derivative Instruments - Effect of Derivative Instruments on Statements of Income and Expenses (Detail) - Currency Futures Contracts [Member] - Not Designated as Hedging Instrument [Member] - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Derivative Instruments, Gain (Loss) [Line Items]
Futures contracts, realized gain (loss)	$ 3,647,504	$ (933,778)
Futures contracts, unrealized gain (loss)	(5,754,839)	7,045,633
Future Contracts, Net Realized and Unrealized Gain (Loss)	$ (2,107,335)	$ 6,111,855