Trading Activities - Trading Gains and Losses, by Market Sector, on Derivative Instruments (Detail) - USD ($)	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019
Derivative [Line Items]
Total trading results	$ (263,196)	$ 810,803
Commodity [Member]
Derivative [Line Items]
Total trading results	1,947,325	(1,273,095)
Equity [Member]
Derivative [Line Items]
Total trading results	(6,022,671)	582,351
Currencies [Member]
Derivative [Line Items]
Total trading results	375,743	(420,821)
Interest Rates [Member]
Derivative [Line Items]
Total trading results	$ 3,436,407	$ 1,922,368

Aggregate net gain and losses (whether realized or unrealized) on all derivative instruments held for trading purposes whether or not settled physically.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4F
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624186-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 45
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=117331979&loc=d3e41322-113958

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration