Summary of Significant Accounting Policies - Summary of the Tiered Valuation Input Levels (Detail) - USD ($)	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
United States Treasury Obligations	$ 700,599,334	$ 846,158,812
Money Market Mutual Fund	33,096,938	3,786,312
Total Investments, at value (cost $733,746,100 and $849,976,394, respectively)	733,696,272	849,945,124
Currency Futures Contracts	(10,539,511)	1,988,810
Total Investments	723,156,761	851,933,934
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money Market Mutual Fund	33,096,938	3,786,312
Total Investments, at value (cost $733,746,100 and $849,976,394, respectively)	33,096,938	3,786,312
Currency Futures Contracts	(10,539,511)	1,988,810
Total Investments	22,557,427	5,775,122
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
United States Treasury Obligations	700,599,334	846,158,812
Total Investments, at value (cost $733,746,100 and $849,976,394, respectively)	700,599,334	846,158,812
Total Investments	$ 700,599,334	$ 846,158,812