Derivative Instruments (Schedule Of Average Notional Value By Sector Of Futures And Forward Currency Contracts) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Long Positions [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	$ 254,397,495	$ 322,017,943
Long Positions [Member] | Futures Contracts [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	225,456,956	284,228,921
Long Positions [Member] | Energies [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	10,894,122	8,715,389
Long Positions [Member] | Grains [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	2,915,933	2,708,704
Long Positions [Member] | Interest Rates [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	145,964,175	211,918,524
Long Positions [Member] | Livestock [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	197,170	340,200
Long Positions [Member] | Metals [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	12,006,013	642,773
Long Positions [Member] | Softs [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	1,026,203	248,158
Long Positions [Member] | Stock Indices [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	52,453,340	59,655,173
Long Positions [Member] | Forward Currency Contracts [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	28,940,539	37,789,022
Short Positions [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	130,543,482	272,429,036
Short Positions [Member] | Futures Contracts [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	101,974,034	207,020,849
Short Positions [Member] | Energies [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	7,052,201	21,243,773
Short Positions [Member] | Grains [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	4,807,045	8,729,568
Short Positions [Member] | Interest Rates [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	72,365,293	117,938,548
Short Positions [Member] | Livestock [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	6,537	617,817
Short Positions [Member] | Metals [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	3,073,785	11,524,551
Short Positions [Member] | Softs [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	1,226,488	3,406,558
Short Positions [Member] | Stock Indices [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	13,442,685	43,560,034
Short Positions [Member] | Forward Currency Contracts [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	$ 28,569,448	$ 65,408,187