Additional Valuation Information - Summary of the Tiered Valuation Input Levels (Detail) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
United States Treasury Obligations	$ 528,403,254	$ 846,158,812
Exchange-Traded Fund	80,128,450
Money Market Mutual Fund	35,038,589	3,786,312
Total Investments	643,570,293	849,945,124
Currency Futures Contracts	6,255,165	1,988,810
Total Investments	649,825,458	851,933,934
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Exchange-Traded Fund	80,128,450
Money Market Mutual Fund	35,038,589	3,786,312
Total Investments	115,167,039	3,786,312
Currency Futures Contracts	6,255,165	1,988,810
Total Investments	121,422,204	5,775,122
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
United States Treasury Obligations	528,403,254	846,158,812
Total Investments	528,403,254	846,158,812
Total Investments	$ 528,403,254	$ 846,158,812