FAIR VALUE OF FINANCIAL INSTRUMENTS (Tables)

12 Months Ended

Dec. 31, 2012

Fair Value Of Financial Instruments [Abstract]

Valuation of Securities Using the Fair Value Hierarchy

The following table summarizes the valuation of US12NG’s securities at December 31, 2012 using the fair value hierarchy:

At December 31, 2012	Total			Level I			Level II		Level III
Short-Term Investments	$	23,922,430		$	23,922,430		$	—	$	—
Exchange-Traded Futures Contracts
United States Contracts		(906,580	)		(906,580	)		—		—

During the year ended December 31, 2012, there were no transfers between Level I and Level II.

The following table summarizes the valuation of US12NG’s securities at December 31, 2011 using the fair value hierarchy:

At December 31, 2011	Total			Level I			Level II		Level III
Short-Term Investments	$	12,278,369		$	12,278,369		$	—	$	—
Exchange-Traded Futures Contracts
United States Contracts		(8,583,320	)		(8,583,320	)		—		—

Fair Value of Derivative Instruments

Fair Value of Derivative Instruments

Derivatives not Accounted for as Hedging Instruments	Statements of Financial Condition Location	Fair Value At December 31, 2012			Fair Value At December 31, 2011
Futures - Commodity Contracts	Assets	$	(906,580	)	$	(8,583,320	)

Effect of Derivative Instruments on the Condensed Statements of Operations

The Effect of Derivative Instruments on the Statements of Operations

		For the year ended December 31, 2012					For the year ended December 31, 2011						For the year ended December 31, 2010
Derivatives not Accounted for as Hedging Instruments	Location of Gain or (Loss) on Derivatives Recognized in Income	Realized Gain or (Loss) on Derivatives Recognized in Income			Change in Unrealized Gain or (Loss) on Derivatives Recognized in Income		Realized Gain or (Loss) on Derivatives Recognized in Income			Change in Unrealized Gain or (Loss) on Derivatives Recognized in Income			Realized Gain or (Loss) on Derivatives Recognized in Income			Change in Unrealized Gain or (Loss) on Derivatives Recognized in Income
Futures - Commodity Contracts	Realized loss on closed positions	$	(12,161,650	)			$	(7,653,100	)				$	(9,574,510	)
	Change in unrealized gain (loss) on open positions				$	7,676,740				$	(6,408,260	)				$	(3,837,730	)