XML 46 R29.htm IDEA: XBRL DOCUMENT v3.19.1
Additional Valuation Information - Summary of the Tiered Valuation Input Levels (Detail) - USD ($)
Mar. 31, 2019
Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
United States Treasury Obligations $ 273,523,483 $ 409,384,745
Exchange-Traded Fund 79,855,930 79,818,080
Money Market Mutual Fund 19,403,213 22,398,721
Total Investments in Securities 372,782,626 511,601,546
Currency Futures Contracts, Depreciation   (4,534,517)
Currency Futures Contracts 2,511,116  
Total Investments 375,293,742 507,067,029
Level 1 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Exchange-Traded Fund 79,855,930 79,818,080
Money Market Mutual Fund 19,403,213 22,398,721
Total Investments in Securities 99,259,143 102,216,801
Currency Futures Contracts, Depreciation   (4,534,517)
Currency Futures Contracts 2,511,116  
Total Investments 101,770,259 97,682,284
Level 2 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
United States Treasury Obligations 273,523,483 409,384,745
Total Investments in Securities 273,523,483 409,384,745
Total Investments $ 273,523,483 $ 409,384,745