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Condensed Schedule of Investments	Mar. 31, 2017 USD ($) Number
Unrealized Gain (Loss) on Open Commodity Contracts	$ 22,140,010
Open Futures Contracts, Long [Member] | United States [Member] | ICE Natural Gas Futures LD1 H May 2017 contracts, expiring May 2017
Number of Contracts | Number	20,000
Unrealized Gain (Loss) on Open Commodity Contracts	$ 8,115,000
% of Partners' Capital	1.76%
Open Futures Contracts, Long [Member] | United States [Member] | NYMEX Natural Gas Futures NG May 2017 contracts, expiring April 2017
Number of Contracts | Number	9,442
Unrealized Gain (Loss) on Open Commodity Contracts	$ 14,025,010
% of Partners' Capital	3.05%
Total Open Futures Contracts [Member] | Open Futures Contracts, Long [Member] | United States [Member]
Number of Contracts | Number	29,442	[1]
Unrealized Gain (Loss) on Open Commodity Contracts	$ 22,140,010	[1]
% of Partners' Capital	4.81%	[1]
Cash Equivalents [Member] | United States [Member]
Market Value	$ 424,441,352
% of Partners' Capital	92.13%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member]
Market Value	$ 404,441,352
% of Partners' Capital	87.79%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.46%, 4/06/2017 [Member]
Principal Amount	$ 20,000,000
Market Value	$ 19,998,736
% of Partners' Capital	4.34%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.47%, 4/13/2017 [Member]
Principal Amount	$ 25,000,000
Market Value	$ 24,996,083
% of Partners' Capital	5.43%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.46%, 4/20/2017 [Member]
Principal Amount	$ 25,000,000
Market Value	$ 24,993,997
% of Partners' Capital	5.42%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.47%, 4/27/2017 [Member]
Principal Amount	$ 25,000,000
Market Value	$ 24,991,604
% of Partners' Capital	5.42%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.49%, 5/04/2017 [Member]
Principal Amount	$ 20,000,000
Market Value	$ 19,990,971
% of Partners' Capital	4.34%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.55%, 5/11/2017 [Member]
Principal Amount	$ 20,000,000
Market Value	$ 19,987,889
% of Partners' Capital	4.34%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.60%, 5/18/2017 [Member]
Principal Amount	$ 20,000,000
Market Value	$ 19,984,464
% of Partners' Capital	4.34%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.61%, 5/25/2017 [Member]
Principal Amount	$ 20,000,000
Market Value	$ 19,981,775
% of Partners' Capital	4.34%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.60%, 6/01/2017 [Member]
Principal Amount	$ 25,000,000
Market Value	$ 24,974,795
% of Partners' Capital	5.42%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.62%, 6/08/2017 [Member]
Principal Amount	$ 20,000,000
Market Value	$ 19,976,767
% of Partners' Capital	4.34%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.65%, 6/15/2017 [Member]
Principal Amount	$ 25,000,000
Market Value	$ 24,966,406
% of Partners' Capital	5.42%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.64%, 6/22/2017 [Member]
Principal Amount	$ 20,000,000
Market Value	$ 19,970,844
% of Partners' Capital	4.33%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.60%, 6/29/2017 [Member]
Principal Amount	$ 15,000,000
Market Value	$ 14,977,750
% of Partners' Capital	3.25%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.62%, 7/06/2017 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,983,600
% of Partners' Capital	2.17%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.59%, 7/13/2017 [Member]
Principal Amount	$ 15,000,000
Market Value	$ 14,974,894
% of Partners' Capital	3.25%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.61%, 7/20/2017 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,981,514
% of Partners' Capital	2.17%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.60%, 7/27/2017 [Member]
Principal Amount	$ 5,000,000
Market Value	$ 4,990,331
% of Partners' Capital	1.08%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.61%, 8/10/2017 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,977,803
% of Partners' Capital	2.17%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.65%, 8/17/2017 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,975,083
% of Partners' Capital	2.16%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.67%, 8/24/2017 [Member]
Principal Amount	$ 15,000,000
Market Value	$ 14,959,521
% of Partners' Capital	3.25%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.76%, 8/31/2017 [Member]
Principal Amount	$ 15,000,000
Market Value	$ 14,952,183
% of Partners' Capital	3.25%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.84%, 9/07/2017 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,962,900
% of Partners' Capital	2.16%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.87%, 9/21/2017 [Member]
Principal Amount	$ 10,000,000
Market Value	$ 9,958,192
% of Partners' Capital	2.16%
Cash Equivalents [Member] | United States [Member] | US Treasury Securities [Member] | U.S. Treasury Bills 0.89%, 9/28/2017 [Member]
Principal Amount	$ 15,000,000
Market Value	$ 14,933,250
% of Partners' Capital	3.24%
Cash Equivalents [Member] | United States [Member] | Money Market Funds [Member]
Market Value	$ 20,000,000
% of Partners' Capital	4.34%
Cash Equivalents [Member] | United States [Member] | Money Market Funds [Member] | Fidelity Investments Money Market Funds - Government Portfolio [Member]
Principal Amount	$ 10,000,000
Market Value	$ 10,000,000
% of Partners' Capital	2.17%
Cash Equivalents [Member] | United States [Member] | Money Market Funds [Member] | Goldman Sachs Financial Square Funds - Government Fund - Class FS [Member]
Principal Amount	$ 10,000,000
Market Value	$ 10,000,000
% of Partners' Capital	2.17%
[1] Collateral amounted to $44,975,772 on open futures contracts.

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