CONDENSED SCHEDULE OF INVESTMENTS (Unaudited) (Parenthetical) - USD ($)	3 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018
Investment Owned
Fixed income securities deposited with futures brokers	$ 21,948,564	$ 22,932,456
Fixed income securities deposited with interbank market makers	128,398,859	133,198,658
U.S. Treasury Bills [Member]
Investment Owned
Fixed income securities deposited with interbank market makers	8,482,732
Fixed Income Securities [Member]
Investment Owned
Cost	150,200,787	156,354,447
Fixed Income Securities [Member] | Asset Backed Securities [Member]
Investment Owned
Cost	11,217,249	11,532,711
Fixed Income Securities [Member] | Bank Deposits [Member]
Investment Owned
Cost	734,999	2,250,068
Fixed Income Securities [Member] | Commercial Paper [Member]
Investment Owned
Cost	55,436,386	49,829,535
Fixed Income Securities [Member] | Commercial Paper [Member] | Ireland [Member] | Financials [Member]
Investment Owned
Cost	1,185,000
Fixed Income Securities [Member] | Commercial Paper [Member] | Japan [Member] | Financials [Member]
Investment Owned
Cost	583,157
Fixed Income Securities [Member] | Commercial Paper [Member] | Switzerland [Member] | Financials [Member]
Investment Owned
Cost	1,613,614	1,590,983
Fixed Income Securities [Member] | Commercial Paper [Member] | United States [Member]
Investment Owned
Cost	52,054,615	48,238,552
Fixed Income Securities [Member] | Corporate Bonds [Member]
Investment Owned
Cost	52,388,021	62,077,646
Fixed Income Securities [Member] | Corporate Bonds [Member] | Australia [Member] | Financials [Member]
Investment Owned
Cost	964,288	364,957
Fixed Income Securities [Member] | Corporate Bonds [Member] | Canada [Member]
Investment Owned
Cost	4,957,860
Fixed Income Securities [Member] | Corporate Bonds [Member] | Canada [Member] | Financials [Member]
Investment Owned
Cost		6,289,499
Fixed Income Securities [Member] | Corporate Bonds [Member] | Germany [Member] | Consumer Discretionary [Member]
Investment Owned
Cost	2,296,763
Fixed Income Securities [Member] | Corporate Bonds [Member] | Japan [Member] | Financials [Member]
Investment Owned
Cost	2,047,779	2,043,076
Fixed Income Securities [Member] | Corporate Bonds [Member] | United Kingdom [Member]
Investment Owned
Cost	3,336,718	4,041,771
Fixed Income Securities [Member] | Corporate Bonds [Member] | United States [Member]
Investment Owned
Cost	38,784,613	49,338,343
Fixed Income Securities [Member] | Government and Agency Obligations [Member]
Investment Owned
Cost	30,424,132	30,664,487
Fixed Income Securities [Member] | Government and Agency Obligations [Member] | United States [Member] | U.S. Treasury Bills [Member]
Investment Owned
Fixed income securities deposited with futures brokers	21,948,564	22,932,456
Fixed income securities deposited with interbank market makers	8,482,732	7,730,616
Fixed Income Securities [Member] | Government and Agency Obligations [Member] | United States [Member] | U.S. Treasury Bills [Member] | U.S. Treasury Bills Due 07/18/2019 [Member]
Investment Owned
Maturity face value	$ 7,685,000
Due date	Jul. 18, 2019
Fixed Income Securities [Member] | Government and Agency Obligations [Member] | United States [Member] | U.S. Treasury Bills [Member] | U.S. Treasury Bills Due 08/15/2019 [Member]
Investment Owned
Maturity face value	$ 13,167,000
Due date	Aug. 15, 2019
Fixed Income Securities [Member] | Government and Agency Obligations [Member] | United States [Member] | U.S. Treasury Bills [Member] | U.S. Treasury Bills Due 09/19/2019 [Member]
Investment Owned
Maturity face value	$ 9,665,000
Due date	Sep. 19, 2019
Fixed Income Securities [Member] | Government and Agency Obligations [Member] | United States [Member] | U.S. Treasury Bills [Member] | U.S. Treasury Bills Due 01/17/2019 [Member]
Investment Owned
Maturity face value		$ 5,560,000
Due date		Jan. 17, 2019
Fixed Income Securities [Member] | Government and Agency Obligations [Member] | United States [Member] | U.S. Treasury Bills [Member] | U.S. Treasury Bills Due 02/21/2019 [Member]
Investment Owned
Maturity face value		$ 14,620,000
Due date		Feb. 21, 2019
Fixed Income Securities [Member] | Government and Agency Obligations [Member] | United States [Member] | U.S. Treasury Bills [Member] | U.S. Treasury Bills Due 03/28/2019 [Member]
Investment Owned
Maturity face value		$ 10,597,500
Due date		Mar. 28, 2019
Short Term Investments [Member]
Investment Owned
Cost	$ 7,073	$ 2,208
Short Term Investments [Member] | Money Market Funds [Member] | United States [Member]
Investment Owned
Cost	$ 7,073	$ 2,208