Derivative Instruments (Schedule Of Trading Gains (Losses) Of Futures And Forward Currency Contracts) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	$ (26,012,333)	$ 2,565,666
Futures Contracts [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	(26,918,024)	4,244,545
Energies [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	7,225,539	(3,290,498)
Grains [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	538,904	420,751
Interest Rates [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	(2,494,946)	6,873,685
Livestock [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	284,010	(4,950)
Metals [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	(59,977)	(539,135)
Softs [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	1,534	65,006
Stock Indices [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	(32,413,088)	719,686
Forward Currency Contracts [Member]
Derivative [Line Items]
Trading gains (losses) of futures and forward currency contracts	$ 905,691	$ (1,678,879)