Trading Activities - Gross Fair Values of Derivative Instruments of Futures and Forward Contracts Traded (Detail) - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Futures Contracts [Member]
Derivative [Line Items]
Total unrealized appreciation on open contracts		$ 9,793,492
Total unrealized depreciation on open contracts		(4,789,432)
Net unrealized appreciation (depreciation) on open contracts		5,004,060
Energy [Member] \| Futures Contracts [Member]
Derivative [Line Items]
Total unrealized appreciation on open contracts		4,510,786
Total unrealized depreciation on open contracts		(787,785)
Grains [Member] \| Futures Contracts [Member]
Derivative [Line Items]
Total unrealized appreciation on open contracts		629,298
Total unrealized depreciation on open contracts		(29,437)
Indices [Member] \| Futures Contracts [Member]
Derivative [Line Items]
Total unrealized appreciation on open contracts		2,719,041
Total unrealized depreciation on open contracts		(1,479,383)
Interest Rates U.S. [Member] \| Futures Contracts [Member]
Derivative [Line Items]
Total unrealized appreciation on open contracts		71,430
Total unrealized depreciation on open contracts		(757,358)
Interest Rates Non-U.S. [Member] \| Futures Contracts [Member]
Derivative [Line Items]
Total unrealized appreciation on open contracts		641,412
Total unrealized depreciation on open contracts		(1,322,106)
Livestock [Member] \| Futures Contracts [Member]
Derivative [Line Items]
Total unrealized depreciation on open contracts		(27,290)
Metals [Member] \| Futures Contracts [Member]
Derivative [Line Items]
Total unrealized appreciation on open contracts		666,037
Total unrealized depreciation on open contracts		(263,285)
Softs [Member] \| Futures Contracts [Member]
Derivative [Line Items]
Total unrealized appreciation on open contracts		555,488
Total unrealized depreciation on open contracts		(122,788)
Forward Contracts [Member]
Derivative [Line Items]
Total unrealized appreciation on open contracts	$ 137,302	11,774,122
Total unrealized depreciation on open contracts	(108,245)	(10,900,848)
Net unrealized appreciation (depreciation) on open contracts	29,057	873,274
Forward Contracts [Member] \| Metals [Member]
Derivative [Line Items]
Total unrealized appreciation on open contracts	137,302	3,586,972
Total unrealized depreciation on open contracts	$ (108,245)	(3,570,209)
Forward Contracts [Member] \| Currencies [Member]
Derivative [Line Items]
Total unrealized appreciation on open contracts		8,187,150
Total unrealized depreciation on open contracts		$ (7,330,639)

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No definition available.

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- Definition

This element represents the excess of the cost (face amount, notional amount) of an investment (security, contract) over its fair value which deficiency has not been recognized in earnings of the entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 320
-Section S99
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=50485924&loc=SL6090603-123010

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- Definition

This element represents the net excess or deficiency of the fair value of an investment (security, contract) over or under its cost (face amount, notional amount), respectively, which excess value or deficiency has not been recognized in earnings of the entity.

+ References

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