Condensed Schedule of Investments (Parenthetical)	9 Months Ended
	Sep. 30, 2015 USD ($)
Debt Instrument, Collateral Amount	$ 2,957,554
Cash Equivalents [Member] | Us Treasury Securities [Member] | U.S. Treasury Bills: 0.19%, 2/04/2016 [Member]
Expiration date	2/04/2016
Interest Rate	0.19%
Cash Equivalents [Member] | Us Treasury Securities [Member] | U.S. Treasury Bills: 0.22%, 2/11/2016 [Member]
Expiration date	2/11/2016
Interest Rate	0.22%
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG November 2015 contracts, expiring October 2015 [Member]
Expiration date	October 2015
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG December 2015 contracts, expiring November 2015 [Member]
Expiration date	November 2015
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG January 2016 contracts, expiring December 2015 [Member]
Expiration date	December 2015
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG February 2016 contracts, expiring January 2016 [Member]
Expiration date	January 2016
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG March 2016 contracts, expiring February 2016 [Member]
Expiration date	February 2016
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG April 2016 contracts, expiring March 2016 [Member]
Expiration date	March 2016
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG May 2016 contracts, expiring April 2016 [Member]
Expiration date	April 2016
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG June 2016 contracts, expiring May 2016 [Member]
Expiration date	May 2016
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG July 2016 contracts, expiring June 2016 [Member]
Expiration date	June 2016
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG August 2016 contracts, expiring July 2016 [Member]
Expiration date	July 2016
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG September 2016 contracts, expiring August 2016 [Member]
Expiration date	August 2016
Open Futures Contracts, Long [Member] | United State [Member] | NYMEX Natural Gas Futures NG October 2016 contracts, expiring September 2016 [Member]
Expiration date	September 2016