Trading Activities and Related Risks (Details) (USD $)	Mar. 31, 2014		Dec. 31, 2013
Total	$ 481,905,196		$ 573,547,299
% of Partners' Capital (Net Asset Value) (in percent)	61.66%		65.15%
United States [Member]
Total	332,954,846		399,169,621
% of Partners' Capital (Net Asset Value) (in percent)	42.59%		45.35%
Netherlands [Member]
Total	30,722,043		40,422,010
% of Partners' Capital (Net Asset Value) (in percent)	3.93%		4.59%
Canada [Member]
Total	12,627,980		29,082,846
% of Partners' Capital (Net Asset Value) (in percent)	1.62%		3.30%
Great Britain [Member]
Total	22,878,144		18,621,105
% of Partners' Capital (Net Asset Value) (in percent)	2.93%		2.12%
Japan [Member]
Total	17,495,830		14,955,517
% of Partners' Capital (Net Asset Value) (in percent)	2.24%		1.70%
Australia [Member]
Total	13,654,777		11,656,547
% of Partners' Capital (Net Asset Value) (in percent)	1.75%		1.32%
France [Member]
Total	6,334,640		8,873,057
% of Partners' Capital (Net Asset Value) (in percent)	0.81%		1.01%
Netherland Antilles [Member]
Total			8,513,655
% of Partners' Capital (Net Asset Value) (in percent)			0.97%
Switzerland [Member]
Total	5,782,364		6,819,730
% of Partners' Capital (Net Asset Value) (in percent)	0.74%		0.77%
Sweden [Member]
Total	6,411,434		6,516,703
% of Partners' Capital (Net Asset Value) (in percent)	0.82%		0.74%
Mexico [Member]
Total	4,034,147		5,928,963
% of Partners' Capital (Net Asset Value) (in percent)	0.52%		0.67%
Denmark [Member]
Total	5,016,313		5,020,114
% of Partners' Capital (Net Asset Value) (in percent)	0.64%		0.57%
Singapore [Member]
Total	3,999,850		4,899,313
% of Partners' Capital (Net Asset Value) (in percent)	0.51%		0.56%
British Virgin Islands [Member]
Total	4,781,124		4,802,760
% of Partners' Capital (Net Asset Value) (in percent)	0.61%		0.55%
Multi-national [Member]
Total			4,004,804
% of Partners' Capital (Net Asset Value) (in percent)			0.45%
China [Member]
Total			3,011,154
% of Partners' Capital (Net Asset Value) (in percent)			0.34%
Norway [Member]
Total	1,249,963		1,249,400
% of Partners' Capital (Net Asset Value) (in percent)	0.16%		0.14%
Spain [Member]
Total	5,072,187
% of Partners' Capital (Net Asset Value) (in percent)	0.65%
Germany [Member]
Total	3,504,590
% of Partners' Capital (Net Asset Value) (in percent)	0.45%
Finland [Member]
Total	2,802,788
% of Partners' Capital (Net Asset Value) (in percent)	0.36%
Luxembourg [Member]
Total	2,582,176
% of Partners' Capital (Net Asset Value) (in percent)	0.33%
U.S. Treasury Securities [Member]
Total	64,041,413		88,102,079
% of Partners' Capital (Net Asset Value) (in percent)	8.19%	[1]	10.01%	[1]
U.S. Treasury Securities [Member] | United States [Member]
Total	64,041,413		88,102,079
Commercial Paper [Member]
Total	65,614,198		65,153,483
% of Partners' Capital (Net Asset Value) (in percent)	8.40%	[1]	7.40%	[1]
Commercial Paper [Member] | United States [Member]
Total	36,333,472		31,009,077
Commercial Paper [Member] | Canada [Member]
Total			2,099,115
Commercial Paper [Member] | Great Britain [Member]
Total	7,998,554		9,196,934
Commercial Paper [Member] | Japan [Member]
Total	4,499,498		4,714,655
Commercial Paper [Member] | Australia [Member]
Total	1,399,726		2,599,946
Commercial Paper [Member] | France [Member]
Total	6,334,640		5,486,017
Commercial Paper [Member] | Sweden [Member]
Total	3,798,495		3,899,026
Commercial Paper [Member] | Singapore [Member]
Total	3,999,850		4,899,313
Commercial Paper [Member] | Norway [Member]
Total	1,249,963		1,249,400
Corporate Notes [Member]
Total	322,764,643		377,666,684
% of Partners' Capital (Net Asset Value) (in percent)	41.30%	[1]	42.89%	[1]
Corporate Notes [Member] | United States [Member]
Total	221,116,497		250,957,531
Corporate Notes [Member] | Netherlands [Member]
Total	29,321,686		40,422,010
Corporate Notes [Member] | Canada [Member]
Total	10,623,663		22,978,564
Corporate Notes [Member] | Great Britain [Member]
Total	14,879,590		9,424,171
Corporate Notes [Member] | Japan [Member]
Total	10,193,735		10,240,862
Corporate Notes [Member] | Australia [Member]
Total	12,255,051		9,056,601
Corporate Notes [Member] | France [Member]
Total			3,387,040
Corporate Notes [Member] | Netherland Antilles [Member]
Total			8,513,655
Corporate Notes [Member] | Switzerland [Member]
Total	2,277,043		2,313,791
Corporate Notes [Member] | Sweden [Member]
Total	611,431		615,818
Corporate Notes [Member] | Mexico [Member]
Total	4,034,147		5,928,963
Corporate Notes [Member] | Denmark [Member]
Total	5,016,313		5,020,114
Corporate Notes [Member] | British Virgin Islands [Member]
Total	4,781,124		4,802,760
Corporate Notes [Member] | Multi-national [Member]
Total			4,004,804
Corporate Notes [Member] | Spain [Member]
Total	5,072,187
Corporate Notes [Member] | Luxembourg [Member]
Total	2,582,176
Certificates of Deposit [Member]
Total	29,484,942		42,625,053
% of Partners' Capital (Net Asset Value) (in percent)	3.79%	[1]	4.85%	[1]
Certificates of Deposit [Member] | United States [Member]
Total	11,463,464		29,100,934
Certificates of Deposit [Member] | Netherlands [Member]
Total	1,400,357
Certificates of Deposit [Member] | Canada [Member]
Total	2,004,317		4,005,167
Certificates of Deposit [Member] | Japan [Member]
Total	2,802,597
Certificates of Deposit [Member] | Switzerland [Member]
Total	3,505,321		4,505,939
Certificates of Deposit [Member] | Sweden [Member]
Total	2,001,508		2,001,859
Certificates of Deposit [Member] | China [Member]
Total			3,011,154
Certificates of Deposit [Member] | Germany [Member]
Total	3,504,590
Certificates of Deposit [Member] | Finland [Member]
Total	$ 2,802,788

[1] Represents the annualized yield at date of purchase for discount securities, the stated coupon rate for coupon-bearing securities, or the stated interest rate for certificates of deposit.