Statements of Financial Condition (Unaudited) (Parenthetical) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Investments in Securities, Cost	$ 377,233,646	$ 365,396,641
Affiliated Investments [Member]
Affiliated Investments, at Cost	232,269,647	245,419,058
US Treasury Bill Securities [Member]
Investments in Securities, Cost	$ 144,963,999	$ 119,977,583