Summary of Significant Accounting Policies	3 Months Ended
Mar. 31, 2013
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	NOTE 2 — SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Revenue Recognition Commodity futures contracts, forward contracts, physical commodities and related options are recorded on the trade date. All such transactions are recorded on the identified cost basis and marked to market daily. Unrealized gains or losses on open contracts are reflected in the condensed statements of financial condition and represent the difference between the original contract amount and the market value (as determined by exchange settlement prices for futures contracts and related options and cash dealer prices at a predetermined time for forward contracts, physical commodities, and their related options) as of the last business day of the year or as of the last date of the condensed financial statements. Changes in the unrealized gains or losses between periods are reflected in the condensed statements of operations. USNG earns interest on its assets denominated in U.S. dollars on deposit with the futures commission merchant at the overnight Federal Funds Rate less 32 basis points. In addition, USNG earns income on funds held at the custodian or futures commission merchant at prevailing market rates earned on such investments. Investments in over-the-counter total return swap contracts (see Note 5) are arrangements to exchange a periodic payment for a market-linked return, each based on a notional amount. To the extent that the total return of the commodity future, security or index underlying the transaction exceeds or falls short of the offsetting periodic payment obligation, USNG receives a payment from, or makes a payment to, the swap counterparty. The over-the-counter swap contracts are valued daily based upon the appreciation or depreciation of the underlying securities subsequent to the effective date of the contract. Changes in the value of the swaps are reported as unrealized gains and losses and periodic payments are recorded as realized gains or losses in the accompanying condensed statements of operations. Brokerage Commissions Brokerage commissions on all open commodity futures contracts are accrued on a full-turn basis. Swap Premiums Upfront fees paid by USNG for over-the-counter swap contracts are reflected on the condensed statements of financial condition and represent payments made upon entering into a swap agreement to compensate for differences between the stated terms of the agreement and prevailing market conditions. The fees are amortized daily over the term of the swap agreement. Income Taxes USNG is not subject to federal income taxes; each partner reports his/her allocable share of income, gain, loss deductions or credits on his/her own income tax return. In accordance with GAAP, USNG is required to determine whether a tax position is more likely than not to be sustained upon examination by the applicable taxing authority, including resolution of any tax related appeals or litigation processes, based on the technical merits of the position. USNG files an income tax return in the U.S. federal jurisdiction, and may file income tax returns in various U.S. states. USNG is not subject to income tax return examinations by major taxing authorities for years before 2009. The tax benefit recognized is measured as the largest amount of benefit that has a greater than fifty percent likelihood of being realized upon ultimate settlement. De-recognition of a tax benefit previously recognized results in USNG recording a tax liability that reduces net assets. However, USNG’s conclusions regarding this policy may be subject to review and adjustment at a later date based on factors including, but not limited to, on-going analysis of and changes to tax laws, regulations and interpretations thereof. USNG recognizes interest accrued related to unrecognized tax benefits and penalties related to unrecognized tax benefits in income tax fees payable, if assessed. No interest expense or penalties have been recognized as of and for the period ended March 31, 2013. Creations and Redemptions Authorized Purchasers may purchase Creation Baskets or redeem Redemption Baskets only in blocks of 100,000 units at a price equal to the NAV of the units calculated shortly after the close of the core trading session on the NYSE Arca on the day the order is placed. USNG receives or pays the proceeds from units sold or redeemed within three business days after the trade date of the purchase or redemption. The amounts due from Authorized Purchasers are reflected in USNG’s condensed statements of financial condition as receivable for units sold, and amounts payable to Authorized Purchasers upon redemption are reflected as payable for units redeemed. Partnership Capital and Allocation of Partnership Income and Losses Profit or loss shall be allocated among the partners of USNG in proportion to the number of units each partner holds as of the close of each month. USCF may revise, alter or otherwise modify this method of allocation as described in the LP Agreement. Calculation of Per Unit Net Asset Value USNG’s per unit NAV is calculated on each NYSE Arca trading day by taking the current market value of its total assets, subtracting any liabilities and dividing that amount by the total number of units outstanding. USNG uses the closing price for the contracts on the relevant exchange on that day to determine the value of contracts held on such exchange. Net Income (Loss) Per Unit Net income (loss) per unit is the difference between the per unit NAV at the beginning of each period and at the end of each period. The weighted average number of units outstanding was computed for purposes of disclosing net income (loss) per weighted average unit. The weighted average units are equal to the number of units outstanding at the end of the period, adjusted proportionately for units added and redeemed based on the amount of time the units were outstanding during such period. There were no units held by USCF at March 31, 2013. Offering Costs Offering costs incurred in connection with the registration of additional units after the initial registration of units are borne by USNG. These costs include registration fees paid to regulatory agencies and all legal, accounting, printing and other expenses associated with such offerings. These costs are accounted for as a deferred charge and thereafter amortized to expense over twelve months on a straight-line basis or a shorter period if warranted. Cash Equivalents Cash equivalents include money market funds and overnight deposits or time deposits with original maturity dates of six months or less. Reclassification Certain amounts in the accompanying condensed financial statements were reclassified to conform to the current presentation. Use of Estimates The preparation of condensed financial statements in conformity with GAAP requires USCF to make estimates and assumptions that affect the reported amount of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed financial statements, and the reported amounts of the revenue and expenses during the reporting period. Actual results may differ from those estimates and assumptions. Other On February 21, 2012, after the close of the NYSE Arca, USNG effected a 4-for-1 reverse unit split and post-split units of USNG began trading on February 22, 2012. The unaudited condensed financial information reported in this quarterly report on Form 10-Q gives effect to the reverse split and the post-split of units as if they had been completed on January 1, 2012. The unaudited condensed financial information and pro forma financial information, as well as the historical financial information as of and for the year ended December 31, 2012, was derived from USNG’s historical financial statements and has been audited by Spicer Jeffries LLP. The financial information as of and for the three months ended March 31, 2013 is unaudited. The condensed financial statements in this quarterly report on Form 10-Q are presented in accordance with Accounting Standards Codification 260 for purposes of presenting the 4-for-1 reverse split on a historical basis for all periods reported.

Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2013

Summary of Significant Accounting Policies

NOTE 2 — SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Revenue Recognition

Commodity futures contracts, forward contracts, physical commodities and related options are recorded on the trade date. All such transactions are recorded on the identified cost basis and marked to market daily. Unrealized gains or losses on open contracts are reflected in the condensed statements of financial condition and represent the difference between the original contract amount and the market value (as determined by exchange settlement prices for futures contracts and related options and cash dealer prices at a predetermined time for forward contracts, physical commodities, and their related options) as of the last business day of the year or as of the last date of the condensed financial statements. Changes in the unrealized gains or losses between periods are reflected in the condensed statements of operations. USNG earns interest on its assets denominated in U.S. dollars on deposit with the futures commission merchant at the overnight Federal Funds Rate less 32 basis points. In addition, USNG earns income on funds held at the custodian or futures commission merchant at prevailing market rates earned on such investments.

Investments in over-the-counter total return swap contracts (see Note 5) are arrangements to exchange a periodic payment for a market-linked return, each based on a notional amount. To the extent that the total return of the commodity future, security or index underlying the transaction exceeds or falls short of the offsetting periodic payment obligation, USNG receives a payment from, or makes a payment to, the swap counterparty. The over-the-counter swap contracts are valued daily based upon the appreciation or depreciation of the underlying securities subsequent to the effective date of the contract. Changes in the value of the swaps are reported as unrealized gains and losses and periodic payments are recorded as realized gains or losses in the accompanying condensed statements of operations.

Brokerage Commissions

Brokerage commissions on all open commodity futures contracts are accrued on a full-turn basis.

Swap Premiums

Upfront fees paid by USNG for over-the-counter swap contracts are reflected on the condensed statements of financial condition and represent payments made upon entering into a swap agreement to compensate for differences between the stated terms of the agreement and prevailing market conditions. The fees are amortized daily over the term of the swap agreement.

Income Taxes

USNG is not subject to federal income taxes; each partner reports his/her allocable share of income, gain, loss deductions or credits on his/her own income tax return.

In accordance with GAAP, USNG is required to determine whether a tax position is more likely than not to be sustained upon examination by the applicable taxing authority, including resolution of any tax related appeals or litigation processes, based on the technical merits of the position. USNG files an income tax return in the U.S. federal jurisdiction, and may file income tax returns in various U.S. states. USNG is not subject to income tax return examinations by major taxing authorities for years before 2009. The tax benefit recognized is measured as the largest amount of benefit that has a greater than fifty percent likelihood of being realized upon ultimate settlement. De-recognition of a tax benefit previously recognized results in USNG recording a tax liability that reduces net assets. However, USNG’s conclusions regarding this policy may be subject to review and adjustment at a later date based on factors including, but not limited to, on-going analysis of and changes to tax laws, regulations and interpretations thereof. USNG recognizes interest accrued related to unrecognized tax benefits and penalties related to unrecognized tax benefits in income tax fees payable, if assessed. No interest expense or penalties have been recognized as of and for the period ended March 31, 2013.

Creations and Redemptions

Authorized Purchasers may purchase Creation Baskets or redeem Redemption Baskets only in blocks of 100,000 units at a price equal to the NAV of the units calculated shortly after the close of the core trading session on the NYSE Arca on the day the order is placed.

USNG receives or pays the proceeds from units sold or redeemed within three business days after the trade date of the purchase or redemption. The amounts due from Authorized Purchasers are reflected in USNG’s condensed statements of financial condition as receivable for units sold, and amounts payable to Authorized Purchasers upon redemption are reflected as payable for units redeemed.

Partnership Capital and Allocation of Partnership Income and Losses

Profit or loss shall be allocated among the partners of USNG in proportion to the number of units each partner holds as of the close of each month. USCF may revise, alter or otherwise modify this method of allocation as described in the LP Agreement.

Calculation of Per Unit Net Asset Value

USNG’s per unit NAV is calculated on each NYSE Arca trading day by taking the current market value of its total assets, subtracting any liabilities and dividing that amount by the total number of units outstanding. USNG uses the closing price for the contracts on the relevant exchange on that day to determine the value of contracts held on such exchange.

Net Income (Loss) Per Unit

Net income (loss) per unit is the difference between the per unit NAV at the beginning of each period and at the end of each period. The weighted average number of units outstanding was computed for purposes of disclosing net income (loss) per weighted average unit. The weighted average units are equal to the number of units outstanding at the end of the period, adjusted proportionately for units added and redeemed based on the amount of time the units were outstanding during such period. There were no units held by USCF at March 31, 2013.

Offering Costs

Offering costs incurred in connection with the registration of additional units after the initial registration of units are borne by USNG. These costs include registration fees paid to regulatory agencies and all legal, accounting, printing and other expenses associated with such offerings. These costs are accounted for as a deferred charge and thereafter amortized to expense over twelve months on a straight-line basis or a shorter period if warranted.

Cash Equivalents

Cash equivalents include money market funds and overnight deposits or time deposits with original maturity dates of six months or less.

Reclassification

Certain amounts in the accompanying condensed financial statements were reclassified to conform to the current presentation.

Use of Estimates

The preparation of condensed financial statements in conformity with GAAP requires USCF to make estimates and assumptions that affect the reported amount of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed financial statements, and the reported amounts of the revenue and expenses during the reporting period. Actual results may differ from those estimates and assumptions.

Other

On February 21, 2012, after the close of the NYSE Arca, USNG effected a 4-for-1 reverse unit split and post-split units of USNG began trading on February 22, 2012. The unaudited condensed financial information reported in this quarterly report on Form 10-Q gives effect to the reverse split and the post-split of units as if they had been completed on January 1, 2012.

The unaudited condensed financial information and pro forma financial information, as well as the historical financial information as of and for the year ended December 31, 2012, was derived from USNG’s historical financial statements and has been audited by Spicer Jeffries LLP. The financial information as of and for the three months ended March 31, 2013 is unaudited. The condensed financial statements in this quarterly report on Form 10-Q are presented in accordance with Accounting Standards Codification 260 for purposes of presenting the 4-for-1 reverse split on a historical basis for all periods reported.

- Definition

The entire disclosure for all significant accounting policies of the reporting entity.

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