Condensed Schedule of Investments (Parenthetical) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Cash Equivalents [Member] | Us Treasury Bill Securities [Member] | Us Treasury Securities [Member]
Interest rate	0.07%	0.10%
Expiration date	3/27/2014	1/17/2013
Open Futures Contracts, Long [Member] | United State [Member]
Debt Instrument, Collateral Amount	$ 949,087	$ 4,416,163
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG February contracts, expiring January [Member]
Expiration date	January 2014	January 2013
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG March contracts, expiring February [Member]
Expiration date	February 2014	February 2013
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG April contracts, expiring March [Member]
Expiration date	March 2014	March 2013
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG May contracts, expiring April [Member]
Expiration date	April 2014	April 2013
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG June contracts, expiring May [Member]
Expiration date	May 2014	May 2013
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG July contracts, expiring June [Member]
Expiration date	June 2014	June 2013
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG August contracts, expiring July [Member]
Expiration date	July 2014	July 2013
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG September contracts, expiring August [Member]
Expiration date	August 2014	August 2013
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG October contracts, expiring September [Member]
Expiration date	September 2014	September 2013
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG November contracts, expiring October [Member]
Expiration date	October 2014	October 2013
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG December contracts, expiring November [Member]
Expiration date	November 2014	November 2013
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG January contracts, expiring December [Member]
Expiration date	December 2014	December 2013