FINANCIAL INSTRUMENTS, OFF-BALANCE SHEET RISKS AND CONTINGENCIES	12 Months Ended
Dec. 31, 2012
Financial Instruments Off Balance Sheet Risks and Contingencies [Abstract]
Financial Instruments, Off-Balance Sheet Risks and Contingencies	NOTE 5 - FINANCIAL INSTRUMENTS, OFF-BALANCE SHEET RISKS AND CONTINGENCIES US12NG engages in the trading of futures contracts, options on futures contracts and cleared swap contracts (collectively, “derivatives”). US12NG is exposed to both market risk, which is the risk arising from changes in the market value of the contracts, and credit risk, which is the risk of failure by another party to perform according to the terms of a contract. US12NG may enter into futures contracts and options on futures contracts and may engage in cleared swap contracts to gain exposure to changes in the value of an underlying commodity. A futures contract obligates the seller to deliver (and the purchaser to accept) the future delivery of a specified quantity and type of a commodity at a specified time and place. Some futures contracts may call for physical delivery of the asset, while others are settled in cash. The contractual obligations of a buyer or seller may generally be satisfied by taking or making physical delivery of the underlying commodity or by making an offsetting sale or purchase of an identical futures contract on the same or linked exchange before the designated date of delivery. The purchase and sale of futures contracts, options on futures contracts and cleared swaps require margin deposits with a futures commission merchant. Additional deposits may be necessary for any loss on contract value. The Commodity Exchange Act requires a futures commission merchant to segregate all customer transactions and assets from the futures commission merchant’s proprietary activities. Futures contracts and cleared swaps involve, to varying degrees, elements of market risk (specifically commodity price risk) and exposure to loss in excess of the amount of variation margin. The face or contract amounts reflect the extent of the total exposure US12NG has in the particular classes of instruments. Additional risks associated with the use of futures contracts are an imperfect correlation between movements in the price of the futures contracts and the market value of the underlying securities and the possibility of an illiquid market for a futures contract. All of the futures contracts held by US12NG were exchange-traded futures contracts through December 31, 2012. The risks associated with exchange-traded contracts are generally perceived to be less than those associated with over-the-counter transactions, since, in over-the-counter transactions, a party must rely solely on the credit of its respective individual counterparties. However, in the future, if US12NG were to enter into non-exchange traded contracts, it would be subject to credit risks associated with counterparty non-performance. Over-the-counter transactions subject US12NG to the credit risk associated with counterparty non-performance. The credit risk from counterparty non-performance associated with such instruments is the net unrealized gain, if any, on the transaction. US12NG has credit risk under its futures contracts since the sole counterparty to all domestic and foreign futures contracts is the clearinghouse for the exchange on which the relevant contracts are traded. In addition, US12NG bears the risk of financial failure by the clearing broker. US12NG’s cash and other property, such as Treasuries, deposited with a futures commission merchant are considered commingled with all other customer funds, subject to the futures commission merchant’s segregation requirements. In the event of a futures commission merchant’s insolvency, recovery may be limited to a pro rata share of segregated funds available. It is possible that the recovered amount could be less than the total of cash and other property deposited. The insolvency of a futures commission merchant could result in the complete loss of US12NG’s assets posted with that futures commission merchant; however, the majority of US12NG’s assets are held in cash and/or cash equivalents with US12NG’s custodian and would not be impacted by the insolvency of a futures commission merchant. The failure or insolvency of US12NG’s custodian, however, could result in a substantial loss of US12NG’s assets. USCF invests a portion of US12NG’s cash in money market funds that seek to maintain a stable per unit NAV. US12NG is exposed to any risk of loss associated with an investment in such money market funds. As of December 31, 2012 and December 31, 2011, US12NG held investments in money market funds in the amounts of $20,522,574 and $10,518,621, respectively. US12NG also holds cash deposits with its custodian. Pursuant to a written agreement with BBH&Co., uninvested overnight cash balances are swept to offshore branches of U.S. regulated and domiciled banks located in Toronto, Canada, London, United Kingdom, Grand Cayman, Cayman Islands and Nassau, Bahamas, which are subject to U.S. regulation and regulatory oversight. As of December 31, 2012 and December 31, 2011, US12NG held cash deposits and investments in Treasuries in the amounts of $23,560,690 and $19,331,650, respectively, with the custodian and futures commission merchant. Some or all of these amounts may be subject to loss should US12NG’s custodian and/or futures commission merchant cease operations. For derivatives, risks arise from changes in the market value of the contracts. Theoretically, US12NG is exposed to market risk equal to the value of futures contracts purchased and unlimited liability on such contracts sold short. As both a buyer and a seller of options, US12NG pays or receives a premium at the outset and then bears the risk of unfavorable changes in the price of the contract underlying the option. US12NG’s policy is to continuously monitor its exposure to market and counterparty risk through the use of a variety of financial, position and credit exposure reporting controls and procedures. In addition, US12NG has a policy of requiring review of the credit standing of each broker or counterparty with which it conducts business. The financial instruments held by US12NG are reported in its statements of financial condition at market or fair value, or at carrying amounts that approximate fair value, because of their highly liquid nature and short-term maturity.

FINANCIAL INSTRUMENTS, OFF-BALANCE SHEET RISKS AND CONTINGENCIES

12 Months Ended

Dec. 31, 2012

Financial Instruments Off Balance Sheet Risks and Contingencies [Abstract]

Financial Instruments, Off-Balance Sheet Risks and Contingencies

NOTE 5 - FINANCIAL INSTRUMENTS, OFF-BALANCE SHEET RISKS AND CONTINGENCIES

US12NG engages in the trading of futures contracts, options on futures contracts and cleared swap contracts (collectively, “derivatives”). US12NG is exposed to both market risk, which is the risk arising from changes in the market value of the contracts, and credit risk, which is the risk of failure by another party to perform according to the terms of a contract.

US12NG may enter into futures contracts and options on futures contracts and may engage in cleared swap contracts to gain exposure to changes in the value of an underlying commodity. A futures contract obligates the seller to deliver (and the purchaser to accept) the future delivery of a specified quantity and type of a commodity at a specified time and place. Some futures contracts may call for physical delivery of the asset, while others are settled in cash. The contractual obligations of a buyer or seller may generally be satisfied by taking or making physical delivery of the underlying commodity or by making an offsetting sale or purchase of an identical futures contract on the same or linked exchange before the designated date of delivery.

The purchase and sale of futures contracts, options on futures contracts and cleared swaps require margin deposits with a futures commission merchant. Additional deposits may be necessary for any loss on contract value. The Commodity Exchange Act requires a futures commission merchant to segregate all customer transactions and assets from the futures commission merchant’s proprietary activities.

Futures contracts and cleared swaps involve, to varying degrees, elements of market risk (specifically commodity price risk) and exposure to loss in excess of the amount of variation margin. The face or contract amounts reflect the extent of the total exposure US12NG has in the particular classes of instruments. Additional risks associated with the use of futures contracts are an imperfect correlation between movements in the price of the futures contracts and the market value of the underlying securities and the possibility of an illiquid market for a futures contract.

All of the futures contracts held by US12NG were exchange-traded futures contracts through December 31, 2012. The risks associated with exchange-traded contracts are generally perceived to be less than those associated with over-the-counter transactions, since, in over-the-counter transactions, a party must rely solely on the credit of its respective individual counterparties. However, in the future, if US12NG were to enter into non-exchange traded contracts, it would be subject to credit risks associated with counterparty non-performance. Over-the-counter transactions subject US12NG to the credit risk associated with counterparty non-performance. The credit risk from counterparty non-performance associated with such instruments is the net unrealized gain, if any, on the transaction. US12NG has credit risk under its futures contracts since the sole counterparty to all domestic and foreign futures contracts is the clearinghouse for the exchange on which the relevant contracts are traded. In addition, US12NG bears the risk of financial failure by the clearing broker.

US12NG’s cash and other property, such as Treasuries, deposited with a futures commission merchant are considered commingled with all other customer funds, subject to the futures commission merchant’s segregation requirements. In the event of a futures commission merchant’s insolvency, recovery may be limited to a pro rata share of segregated funds available. It is possible that the recovered amount could be less than the total of cash and other property deposited. The insolvency of a futures commission merchant could result in the complete loss of US12NG’s assets posted with that futures commission merchant; however, the majority of US12NG’s assets are held in cash and/or cash equivalents with US12NG’s custodian and would not be impacted by the insolvency of a futures commission merchant. The failure or insolvency of US12NG’s custodian, however, could result in a substantial loss of US12NG’s assets.

USCF invests a portion of US12NG’s cash in money market funds that seek to maintain a stable per unit NAV. US12NG is exposed to any risk of loss associated with an investment in such money market funds. As of December 31, 2012 and December 31, 2011, US12NG held investments in money market funds in the amounts of $20,522,574 and $10,518,621, respectively. US12NG also holds cash deposits with its custodian. Pursuant to a written agreement with BBH&Co., uninvested overnight cash balances are swept to offshore branches of U.S. regulated and domiciled banks located in Toronto, Canada, London, United Kingdom, Grand Cayman, Cayman Islands and Nassau, Bahamas, which are subject to U.S. regulation and regulatory oversight. As of December 31, 2012 and December 31, 2011, US12NG held cash deposits and investments in Treasuries in the amounts of $23,560,690 and $19,331,650, respectively, with the custodian and futures commission merchant. Some or all of these amounts may be subject to loss should US12NG’s custodian and/or futures commission merchant cease operations.

For derivatives, risks arise from changes in the market value of the contracts. Theoretically, US12NG is exposed to market risk equal to the value of futures contracts purchased and unlimited liability on such contracts sold short. As both a buyer and a seller of options, US12NG pays or receives a premium at the outset and then bears the risk of unfavorable changes in the price of the contract underlying the option.

US12NG’s policy is to continuously monitor its exposure to market and counterparty risk through the use of a variety of financial, position and credit exposure reporting controls and procedures. In addition, US12NG has a policy of requiring review of the credit standing of each broker or counterparty with which it conducts business.

The financial instruments held by US12NG are reported in its statements of financial condition at market or fair value, or at carrying amounts that approximate fair value, because of their highly liquid nature and short-term maturity.