Consolidated Condensed Schedule of Investments Commercial Paper (Unaudited) (USD $)	Mar. 31, 2014		Dec. 31, 2013
Schedule of Investments [Line Items]
% of Partners' Capital (Net Asset Value)	61.66%		65.15%
Commercial Paper [Member]
Schedule of Investments [Line Items]
Fair Value	$ 65,614,198		$ 65,153,483
% of Partners' Capital (Net Asset Value)	8.40%	[1]	7.40%	[1]
Investment Owned, at Cost	65,581,121		65,122,443
Commercial Paper [Member] | U.S. Commercial Paper [Member]
Schedule of Investments [Line Items]
Fair Value	36,333,472		31,009,077
% of Partners' Capital (Net Asset Value)	4.65%	[1]	3.52%	[1]
Investment Owned, at Cost	36,326,616		31,004,242
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Agricultural [Member] | 0.08% Philip Morris International Inc. Due 2014-04-22 [Member]
Schedule of Investments [Line Items]
Face Value	2,000,000
Fair Value	1,999,905
% of Partners' Capital (Net Asset Value)	0.26%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Banks [Member] | 0.17% HSBC USA Inc. Due 2014-06-09 [Member]
Schedule of Investments [Line Items]
Face Value	2,000,000
Fair Value	1,999,348
% of Partners' Capital (Net Asset Value)	0.26%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Banks [Member] | 0.20% Mizuho Funding LLC Due 2014-05-27 [Member]
Schedule of Investments [Line Items]
Face Value	2,200,000
Fair Value	2,199,333
% of Partners' Capital (Net Asset Value)	0.27%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Banks [Member] | 0.23% Mizuho Funding LLC Due 2014-08-06 [Member]
Schedule of Investments [Line Items]
Face Value	750,000
Fair Value	749,380
% of Partners' Capital (Net Asset Value)	0.09%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Banks [Member] | 0.15% Standard Chartered Bank Due 2014-04-03 [Member]
Schedule of Investments [Line Items]
Face Value	1,400,000
Fair Value	1,399,988
% of Partners' Capital (Net Asset Value)	0.18%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Banks [Member] | 0.12% Wells Fargo & Company Due 2014-04-08 [Member]
Schedule of Investments [Line Items]
Face Value	2,000,000
Fair Value	1,999,953
% of Partners' Capital (Net Asset Value)	0.26%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Banks [Member] | 0.21% Mizuho Funding LLC Due 2014-02-24 [Member]
Schedule of Investments [Line Items]
Face Value			2,200,000
Fair Value			2,199,323
% of Partners' Capital (Net Asset Value)			0.25%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Beverages [Member] | 0.18% Anheuser-Busch In Bev Worldwide Inc. Due 2014-04-15 [Member]
Schedule of Investments [Line Items]
Face Value	2,000,000
Fair Value	1,999,860
% of Partners' Capital (Net Asset Value)	0.26%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Beverages [Member] | 0.18% Bacardi Corporation Due 2014-04-09 [Member]
Schedule of Investments [Line Items]
Face Value	2,000,000
Fair Value	1,999,920
% of Partners' Capital (Net Asset Value)	0.26%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Beverages [Member] | 0.25% Bacardi Corporation Due 2014-01-15 [Member]
Schedule of Investments [Line Items]
Face Value			2,200,000
Fair Value			2,199,786
% of Partners' Capital (Net Asset Value)			0.25%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Beverages [Member] | 0.12% Brown-Forman Corporation Due 2014-01-16 [Member]
Schedule of Investments [Line Items]
Face Value			1,262,000
Fair Value			1,261,937
% of Partners' Capital (Net Asset Value)			0.14%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Diversified Financial Services [Member] | 0.19% Harley-Davidson Financial Services, Inc. Due 2014-04-09 [Member]
Schedule of Investments [Line Items]
Face Value	650,000
Fair Value	649,973
% of Partners' Capital (Net Asset Value)	0.08%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Diversified Financial Services [Member] | 0% ING (U.S.) Funding LLC Due 2014-04-01 [Member]
Schedule of Investments [Line Items]
Face Value	2,000,000
Fair Value	2,000,000
% of Partners' Capital (Net Asset Value)	0.26%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Diversified Financial Services [Member] | 0.21% ING (U.S.) Funding LLC Due 2014-07-07 [Member]
Schedule of Investments [Line Items]
Face Value	2,800,000
Fair Value	2,798,392
% of Partners' Capital (Net Asset Value)	0.35%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Diversified Financial Services [Member] | 0.09% National Rural Utilities Cooperative Finance Corp, Due 2014-05-12 [Member]
Schedule of Investments [Line Items]
Face Value	1,700,000
Fair Value	1,699,826
% of Partners' Capital (Net Asset Value)	0.22%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Diversified Financial Services [Member] | 0.28% VNA Holding Inc. Due 2014-04-29 [Member]
Schedule of Investments [Line Items]
Face Value	1,800,000
Fair Value	1,799,608
% of Partners' Capital (Net Asset Value)	0.23%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Diversified Financial Services [Member] | 0.24% AXA Financial, Inc. Due 2014-01-09 [Member]
Schedule of Investments [Line Items]
Face Value			2,700,000
Fair Value			2,699,856
% of Partners' Capital (Net Asset Value)			0.30%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Diversified Financial Services [Member] | 0.30% VNA Holding Inc. Due 2014-01-14 [Member]
Schedule of Investments [Line Items]
Face Value			1,500,000
Fair Value			1,499,838
% of Partners' Capital (Net Asset Value)			0.17%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Energy [Member] | 1.61% NextEra Energy Capital Holdings, Inc. Due 2014-06-01 [Member]
Schedule of Investments [Line Items]
Face Value	2,000,000
Fair Value	1,999,722
% of Partners' Capital (Net Asset Value)	0.26%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Energy [Member] | 0.11% Oglethorpe Power Corporation Due 2014-04-23 [Member]
Schedule of Investments [Line Items]
Face Value	2,000,000
Fair Value	1,999,866
% of Partners' Capital (Net Asset Value)	0.26%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Energy [Member] | 0.22% ONEOK PARTNERS LP Due 2014-04-08 [Member]
Schedule of Investments [Line Items]
Face Value	1,800,000
Fair Value	1,799,923
% of Partners' Capital (Net Asset Value)	0.23%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Energy [Member] | 0.27% Sempra Energy Global Enterprises Due 2014-04-28 [Member]
Schedule of Investments [Line Items]
Face Value	1,600,000
Fair Value	1,599,676
% of Partners' Capital (Net Asset Value)	0.20%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Energy [Member] | 0.15% SOUTHERN COMPANY FUNDING CORP Due 2014-04-24 [Member]
Schedule of Investments [Line Items]
Face Value	1,339,000
Fair Value	1,338,872
% of Partners' Capital (Net Asset Value)	0.17%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Energy [Member] | 0.20% Devon Energy Corporation Due 2014-01-30 [Member]
Schedule of Investments [Line Items]
Face Value			2,000,000
Fair Value			1,999,678
% of Partners' Capital (Net Asset Value)			0.23%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Energy [Member] | 0.22% Enterprise Products Operating LLC Due 2014-01-10 [Member]
Schedule of Investments [Line Items]
Face Value			2,000,000
Fair Value			1,999,890
% of Partners' Capital (Net Asset Value)			0.23%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Energy [Member] | 0.16% Oglethorpe Power Corporation Due 2014-01-07 [Member]
Schedule of Investments [Line Items]
Face Value			2,200,000
Fair Value			2,199,941
% of Partners' Capital (Net Asset Value)			0.25%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Energy [Member] | 0.25% Sempra Energy Global Enterprises Due 2014-01-23 [Member]
Schedule of Investments [Line Items]
Face Value			2,000,000
Fair Value			1,999,694
% of Partners' Capital (Net Asset Value)			0.23%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Energy [Member] | 0.17% Southern Company Funding Corp. Due 2014-01-07 [Member]
Schedule of Investments [Line Items]
Face Value			2,750,000
Fair Value			2,749,922
% of Partners' Capital (Net Asset Value)			0.31%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Media [Member] | 0.21% CBS Corporation Due 2014-04-02 [Member]
Schedule of Investments [Line Items]
Face Value	2,000,000
Fair Value	1,999,988
% of Partners' Capital (Net Asset Value)	0.26%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Non-profit [Member] | 0.12% Catholic Health Initiatives Due 2014-04-09 [Member]
Schedule of Investments [Line Items]
Face Value	2,300,000
Fair Value	2,299,939
% of Partners' Capital (Net Asset Value)	0.29%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Non-profit [Member] | 0.15% Salvation Army Due 2014-01-06 [Member]
Schedule of Investments [Line Items]
Face Value			2,800,000
Fair Value			2,799,942
% of Partners' Capital (Net Asset Value)			0.31%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Telecommunications [Member] | 0.21% Verizon Communications Inc. Due 2014-01-24 [Member]
Schedule of Investments [Line Items]
Face Value			2,000,000
Fair Value			1,999,732
% of Partners' Capital (Net Asset Value)			0.23%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Automotive [Member] | 0.30% Nissan Motor Acceptance Corp. Due 2014-01-21 [Member]
Schedule of Investments [Line Items]
Face Value			2,200,000
Fair Value			2,199,633
% of Partners' Capital (Net Asset Value)			0.25%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Food [Member] | 0.17% Sysco Corporation Due 2014-01-10 [Member]
Schedule of Investments [Line Items]
Face Value			2,000,000
Fair Value			1,999,915
% of Partners' Capital (Net Asset Value)			0.23%	[1]
Commercial Paper [Member] | U.S. Commercial Paper [Member] | Manufacturing [Member] | 0.15% Stanley Black & Decker, Inc. Due 2014-01-03 [Member]
Schedule of Investments [Line Items]
Face Value			1,200,000
Fair Value			1,199,990
% of Partners' Capital (Net Asset Value)			0.14%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member]
Schedule of Investments [Line Items]
Fair Value	29,280,726		34,144,406
% of Partners' Capital (Net Asset Value)	3.75%	[1]	3.88%	[1]
Investment Owned, at Cost	29,254,505		34,118,201
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Banks [Member] | 0.17% Bank of Tokyo-Mitsubishi UFJ, Ltd. Due 2014-04-24 [Member]
Schedule of Investments [Line Items]
Face Value	2,000,000
Fair Value	1,999,783
% of Partners' Capital (Net Asset Value)	0.26%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Banks [Member] | 0.18% DNB Bank ASA Due 2014-04-07 [Member]
Schedule of Investments [Line Items]
Face Value	1,250,000		1,250,000
Fair Value	1,249,963		1,249,400
% of Partners' Capital (Net Asset Value)	0.16%	[1]	0.14%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Banks [Member] | 0.16% Nordea Bank AB Due 2014-06-02 [Member]
Schedule of Investments [Line Items]
Face Value	2,000,000
Fair Value	1,999,449
% of Partners' Capital (Net Asset Value)	0.26%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Banks [Member] | 0.18% Oversea-Chinese Banking Corporation Ltd Due 2014-04-03 [Member]
Schedule of Investments [Line Items]
Face Value	2,000,000
Fair Value	1,999,980
% of Partners' Capital (Net Asset Value)	0.26%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Banks [Member] | 0.18% Skandinaviska Ensilda Banken AB Due 2014-07-16 [Member]
Schedule of Investments [Line Items]
Face Value	1,800,000
Fair Value	1,799,046
% of Partners' Capital (Net Asset Value)	0.23%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Banks [Member] | 0.21% Sumitomo Mitsui Bank Due 2014-04-21 [Member]
Schedule of Investments [Line Items]
Face Value	2,500,000
Fair Value	2,499,715
% of Partners' Capital (Net Asset Value)	0.32%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Banks [Member] | 0.18% United Overseas Bank Limited Due 2014-04-14 [Member]
Schedule of Investments [Line Items]
Face Value	2,000,000
Fair Value	1,999,870
% of Partners' Capital (Net Asset Value)	0.26%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Banks [Member] | 0.17% Bank of Nova Scotia Due 2014-03-31 [Member]
Schedule of Investments [Line Items]
Face Value			2,100,000
Fair Value			2,099,115
% of Partners' Capital (Net Asset Value)			0.24%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Banks [Member] | 0.15% Bank of Tokyo-Mitsubishi UFJ, Ltd. Due 2014-01-14 [Member]
Schedule of Investments [Line Items]
Face Value			2,015,000
Fair Value			2,014,891
% of Partners' Capital (Net Asset Value)			0.23%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Banks [Member] | 0.15% Commonwealth Bank of Australia Due 2014-01-06 [Member]
Schedule of Investments [Line Items]
Face Value			2,600,000
Fair Value			2,599,946
% of Partners' Capital (Net Asset Value)			0.30%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Banks [Member] | 0.16% DBS Bank Ltd Due 2014-02-27 [Member]
Schedule of Investments [Line Items]
Face Value			2,400,000
Fair Value			2,399,392
% of Partners' Capital (Net Asset Value)			0.27%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Banks [Member] | 0.18% Nordea Bank AB Due 2014-03-03 [Member]
Schedule of Investments [Line Items]
Face Value			2,500,000
Fair Value			2,499,259
% of Partners' Capital (Net Asset Value)			0.28%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Banks [Member] | 0.19% Oversea-Chinese Banking Corporation Ltd Due 2014-01-07 [Member]
Schedule of Investments [Line Items]
Face Value			2,500,000
Fair Value			2,499,921
% of Partners' Capital (Net Asset Value)			0.28%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Banks [Member] | 0.15% Skandinaviska Enskilda Banken AB Due 2014-02-10 [Member]
Schedule of Investments [Line Items]
Face Value			1,400,000
Fair Value			1,399,767
% of Partners' Capital (Net Asset Value)			0.16%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Banks [Member] | 0.15% Sumitomo Mitsui Bank Due 2014-01-22 [Member]
Schedule of Investments [Line Items]
Face Value			2,700,000
Fair Value			2,699,764
% of Partners' Capital (Net Asset Value)			0.31%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Beverages [Member] | 0.27% Diageo Capital PLC Due 2014-05-27 [Member]
Schedule of Investments [Line Items]
Face Value	2,000,000
Fair Value	1,999,160
% of Partners' Capital (Net Asset Value)	0.26%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Energy [Member] | 0.48% Electricite de France Due 2015-01-02 [Member]
Schedule of Investments [Line Items]
Face Value	4,100,000
Fair Value	4,084,789
% of Partners' Capital (Net Asset Value)	0.51%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Energy [Member] | 0.17% GDF Suez Due 2014-04-15 [Member]
Schedule of Investments [Line Items]
Face Value	2,250,000
Fair Value	2,249,851
% of Partners' Capital (Net Asset Value)	0.29%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Energy [Member] | 0.55% Electricite de France Due 2015-01-02 [Member]
Schedule of Investments [Line Items]
Face Value			2,500,000
Fair Value			2,486,500
% of Partners' Capital (Net Asset Value)			0.28%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Energy [Member] | 0.20% GDF Suez Due 2014-01-30 [Member]
Schedule of Investments [Line Items]
Face Value			3,000,000
Fair Value			2,999,517
% of Partners' Capital (Net Asset Value)			0.34%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Consumer Products [Member] | 0.14% Reckitt Benckiser Treasury Services PLC Due 2014-04-17 [Member]
Schedule of Investments [Line Items]
Face Value	4,000,000
Fair Value	3,999,736
% of Partners' Capital (Net Asset Value)	0.50%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Consumer Products [Member] | 0.43% Reckitt Benckiser Treasury Services PLC Due 2014-03-04 [Member]
Schedule of Investments [Line Items]
Face Value			1,600,000
Fair Value			1,599,544
% of Partners' Capital (Net Asset Value)			0.18%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Consumer Products [Member] | 0.40% Reckitt Benckiser Treasury Services PLC Due 2014-04-17 [Member]
Schedule of Investments [Line Items]
Face Value			4,000,000
Fair Value			3,997,670
% of Partners' Capital (Net Asset Value)			0.46%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Insurance [Member] | 0.15% Prudential PLC Due 2014-05-12 [Member]
Schedule of Investments [Line Items]
Face Value	2,000,000
Fair Value	1,999,658
% of Partners' Capital (Net Asset Value)	0.26%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Insurance [Member] | 0.16% Prudential PLC Due 2014-01-08 [Member]
Schedule of Investments [Line Items]
Face Value			1,500,000
Fair Value			1,499,953
% of Partners' Capital (Net Asset Value)			0.17%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Telecommunications [Member] | 0.16% Telstra Corporation Limited Due 2014-05-15 [Member]
Schedule of Investments [Line Items]
Face Value	1,400,000
Fair Value	1,399,726
% of Partners' Capital (Net Asset Value)	0.18%	[1]
Commercial Paper [Member] | Foreign Commercial Paper [Member] | Food [Member] | 0.25% Tesco Treasury Services PLC Due 2014-01-17 [Member]
Schedule of Investments [Line Items]
Face Value			2,100,000
Fair Value			$ 2,099,767
% of Partners' Capital (Net Asset Value)			0.24%	[1]

[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.