Derivative Instruments (Schedule Of Average Notional Value By Sector Of Futures And Forward Currency Contracts) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Long Positions [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	$ 341,308,558	$ 278,541,276
Long Positions [Member] | Futures Contracts [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	295,587,619	245,595,287
Long Positions [Member] | Energies [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	8,911,277	10,710,588
Long Positions [Member] | Grains [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	4,539,716	2,227,178
Long Positions [Member] | Interest Rates [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	210,815,600	167,096,856
Long Positions [Member] | Livestock [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	155,158	320,490
Long Positions [Member] | Metals [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	13,333,707	2,054,703
Long Positions [Member] | Softs [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	1,190,563	186,119
Long Positions [Member] | Stock Indices [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	56,641,598	62,999,353
Long Positions [Member] | Forward Currency Contracts [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	45,720,939	32,945,989
Short Positions [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	104,707,100	299,494,896
Short Positions [Member] | Futures Contracts [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	80,582,114	218,037,195
Short Positions [Member] | Energies [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	6,718,330	16,083,367
Short Positions [Member] | Grains [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	4,543,772	9,724,495
Short Positions [Member] | Interest Rates [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	54,680,755	138,507,852
Short Positions [Member] | Livestock [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	139,923	717,053
Short Positions [Member] | Metals [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	2,316,727	9,688,499
Short Positions [Member] | Softs [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	1,040,801	3,815,158
Short Positions [Member] | Stock Indices [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	11,141,806	39,500,771
Short Positions [Member] | Forward Currency Contracts [Member]
Derivative [Line Items]
Average notional amount of futures and forward currency contracts	$ 24,124,986	$ 81,457,701