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Euro Deposits - Additional Information (Detail)
3 Months Ended 12 Months Ended
Mar. 31, 2021
USD ($)
Mar. 31, 2021
EUR (€)
Mar. 31, 2020
USD ($)
Dec. 31, 2020
EUR (€)
Mar. 31, 2021
EUR (€)
Dec. 31, 2020
USD ($)
Dec. 31, 2020
EUR (€)
Cash And Cash Equivalents [Abstract]              
Annual nominal rate (0.50%)       (0.50%)    
Principal deposits $ 73,791,699 € 61,012,147 $ 72,662,459 € 428,947,584      
Principal redemptions 79,236,071 65,672,692 $ 83,758,009 414,936,856      
Withdrawals (to pay expenses)   € 618,732   € 2,238,467      
Deposits, interest bearing $ 308,634,165       € 262,600,454 $ 327,764,221 € 267,879,731