Fair Value Measurements (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Fair Value Measurements
Investments Owned, Fair Value	$ 87,511,963	$ 116,297,654
Recurring basis
Fair Value Measurements
Total	138,733,348	182,678,703
Recurring basis \| Futures Contracts
Fair Value Measurements
Open derivative contracts, fair value	2,279,924	827,595
Recurring basis \| Forward Contracts
Fair Value Measurements
Open derivative contracts, fair value	705	(240,659)
Recurring basis \| Swap Contracts
Fair Value Measurements
Open derivative contracts, fair value	(734,698)	1,168,100
Recurring basis \| Bank deposits
Fair Value Measurements
Cash and cash equivalents		1,101,389
Recurring basis \| U.S. money market fund
Fair Value Measurements
Cash and cash equivalents	3,965,046
Recurring basis \| Foreign commercial paper
Fair Value Measurements
Cash and cash equivalents	1,328,590	5,547,926
Investments Owned, Fair Value		4,008,509
Recurring basis \| U.S. commercial paper
Fair Value Measurements
Cash and cash equivalents	44,381,818	57,976,698
Investments Owned, Fair Value	7,144,238	15,173,266
Recurring basis \| U.S. Government-sponsored enterprises
Fair Value Measurements
Investments Owned, Fair Value	69,209,493	82,472,451
Recurring basis \| U.S. Corporate bonds
Fair Value Measurements
Investments Owned, Fair Value	11,158,232	14,643,428
Recurring basis \| Level 1
Fair Value Measurements
Total	6,244,970	1,928,984
Recurring basis \| Level 1 \| Futures Contracts
Fair Value Measurements
Open derivative contracts, fair value	2,279,924	827,595
Recurring basis \| Level 1 \| Bank deposits
Fair Value Measurements
Cash and cash equivalents		1,101,389
Recurring basis \| Level 1 \| U.S. money market fund
Fair Value Measurements
Cash and cash equivalents	3,965,046
Recurring basis \| Level 2
Fair Value Measurements
Total	132,488,378	180,749,719
Recurring basis \| Level 2 \| Forward Contracts
Fair Value Measurements
Open derivative contracts, fair value	705	(240,659)
Recurring basis \| Level 2 \| Swap Contracts
Fair Value Measurements
Open derivative contracts, fair value	(734,698)	1,168,100
Recurring basis \| Level 2 \| Foreign commercial paper
Fair Value Measurements
Cash and cash equivalents	1,328,590	5,547,926
Investments Owned, Fair Value		4,008,509
Recurring basis \| Level 2 \| U.S. commercial paper
Fair Value Measurements
Cash and cash equivalents	44,381,818	57,976,698
Investments Owned, Fair Value	7,144,238	15,173,266
Recurring basis \| Level 2 \| U.S. Government-sponsored enterprises
Fair Value Measurements
Investments Owned, Fair Value	69,209,493	82,472,451
Recurring basis \| Level 2 \| U.S. Corporate bonds
Fair Value Measurements
Investments Owned, Fair Value	$ 11,158,232	$ 14,643,428

Fair value of the assets less the liabilities of open derivative contracts pledged to counterparties as collateral.

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- Definition

The fair value, as of the balance sheet date, of financial instruments owned by the entity and not pledged to counterparties as collateral. Excludes derivative contracts.

+ References

No definition available.

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- Definition

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash
-URI http://asc.fasb.org/extlink&oid=6506951

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash Equivalents
-URI http://asc.fasb.org/extlink&oid=6507016

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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