Document_And_Entity_Informatio
| Document And Entity Information | 9 Months Ended |
| Sep. 30, 2014 | |
| Document Information [Line Items] | ' |
| Document Type | '10-Q |
| Amendment Flag | 'false |
| Document Period End Date | 30-Sep-14 |
| Document Fiscal Year Focus | '2014 |
| Document Fiscal Period Focus | 'Q3 |
| Entity Registrant Name | 'United States Gasoline Fund, LP |
| Entity Central Index Key | '0001396878 |
| Current Fiscal Year End Date | '--12-31 |
| Entity Filer Category | 'Accelerated Filer |
| Trading Symbol | 'UGA |
| Entity Common Stock, Shares Outstanding | 0 |
Condensed_Statements_of_Financ
| Condensed Statements of Financial Condition (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| Assets | ' | ' |
| Cash and cash equivalents (Notes 2 and 5) | $50,312,319 | $52,193,157 |
| Equity in trading accounts: | ' | ' |
| Cash and cash equivalents | 2,734,210 | 2,053,484 |
| Unrealized gain (loss) on open commodity futures contracts | -1,459,248 | 2,598,553 |
| Dividends receivable | 572 | 628 |
| Receivable from general partner | 68,076 | 137,776 |
| Other assets | 138,782 | 172,060 |
| Total assets | 51,794,711 | 57,155,658 |
| Liabilities and Partners' Capital | ' | ' |
| Professional fees payable | 77,010 | 225,429 |
| General Partner management fees payable (Note 3) | 25,740 | 28,519 |
| Brokerage commissions payable | 1,273 | 1,723 |
| Other liabilities | 2,162 | 2,816 |
| Total liabilities | 106,185 | 258,487 |
| Commitments and Contingencies (Notes 3, 4 and 5) | ' | ' |
| Partners' Capital | ' | ' |
| General Partner | 0 | 0 |
| Limited Partners | 51,688,526 | 56,897,171 |
| Total Partners' Capital | 51,688,526 | 56,897,171 |
| Total liabilities and partners' capital | $51,794,711 | $57,155,658 |
| Limited Partners' shares outstanding | 950,000 | 950,000 |
| Net asset value per share | $54.41 | $59.89 |
| Market value per share | $54.56 | $59.93 |
Condensed_Schedule_of_Investme
| Condensed Schedule of Investments (United States, USD $) | Sep. 30, 2014 | |
| Contracts | ||
| Open Cleared Swap and Futures Contracts | Open Futures Contracts, Long | NYMEX RBOB Gasoline Futures RB November 2014 contracts, expiring October 2014 | ' | |
| Number of contracts | 505 | [1] |
| Unrealized Loss on Open Commodity Contracts | ($1,459,248) | [1] |
| % of Partners' Capital | -2.82% | [1] |
| Cash Equivalents | ' | |
| Market Value | 36,994,331 | |
| % of Partners' Capital | 71.57% | |
| Cash Equivalents | US Treasury Securities | ' | |
| Market Value | 5,999,348 | |
| % of Partners' Capital | 11.61% | |
| Cash Equivalents | US Treasury Securities | US Treasury Bill Securities | ' | |
| Principal Amount | 3,000,000 | |
| Market Value | 2,999,903 | |
| % of Partners' Capital | 5.81% | |
| Cash Equivalents | US Treasury Securities | US Treasury Bill Securities One | ' | |
| Principal Amount | 3,000,000 | |
| Market Value | 2,999,445 | |
| % of Partners' Capital | 5.80% | |
| Cash Equivalents | Money Market Funds | ' | |
| Market Value | 30,994,983 | |
| % of Partners' Capital | 59.96% | |
| Cash Equivalents | Money Market Funds | Fidelity Institutional Government Portfolio, Class I | ' | |
| Principal Amount | 11,063,515 | |
| Market Value | 11,063,515 | |
| % of Partners' Capital | 21.40% | |
| Cash Equivalents | Money Market Funds | Goldman Sachs Financial Square Funds Government Fund, Class FS | ' | |
| Principal Amount | 6,907,119 | |
| Market Value | 6,907,119 | |
| % of Partners' Capital | 13.36% | |
| Cash Equivalents | Money Market Funds | Morgan Stanley Institutional Liquidity Funds, Government Portfolio | ' | |
| Principal Amount | 13,024,349 | |
| Market Value | $13,024,349 | |
| % of Partners' Capital | 25.20% | |
| [1] | Collateral amounted to $2,734,210 on open future contracts. | |
Condensed_Schedule_of_Investme1
| Condensed Schedule of Investments (Parenthetical) (USD $) | 9 Months Ended |
| Sep. 30, 2014 | |
| Debt Instrument, Collateral Amount | 2,734,210 |
| United States | NYMEX RBOB Gasoline Futures RB November 2014 contracts, expiring October 2014 | Open Cleared Swap and Futures Contracts | Open Futures Contracts, Long | ' |
| Expiration date | 'October 2014 |
| United States | US Treasury Bill Securities | US Treasury Securities | Cash Equivalents | ' |
| Interest rate | 0.04% |
| Expiration date | '10/30/2014 |
| United States | US Treasury Bill Securities One | US Treasury Securities | Cash Equivalents | ' |
| Interest rate | 0.05% |
| Expiration date | '2/26/2015 |
Condensed_Statements_of_Operat
| Condensed Statements of Operations (USD $) | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | |
| Gain (loss) on trading of commodity futures contracts: | ' | ' | ' | ' |
| Realized gain (loss) on closed positions | ($5,067,119) | $952,430 | ($54,730) | $3,844,332 |
| Change in unrealized gain (loss) on open positions | -1,499,820 | 1,840,482 | -4,057,801 | -4,114,522 |
| Dividend income | 1,698 | 2,022 | 5,127 | 7,348 |
| Interest income | 1,156 | 993 | 4,071 | 3,733 |
| Other income | 2,450 | 1,400 | 4,200 | 4,550 |
| Total income (loss) | -6,561,635 | 2,797,327 | -4,099,133 | -254,559 |
| Expenses | ' | ' | ' | ' |
| General Partner management fees (Note 3) | 71,065 | 86,656 | 220,169 | 267,729 |
| Professional fees | 58,035 | 51,985 | 130,616 | 188,537 |
| Brokerage commissions | 8,929 | 9,866 | 25,698 | 29,833 |
| Registration fees | 11,709 | 11,709 | 34,745 | 34,745 |
| Other expenses | 4,749 | 5,349 | 14,939 | 16,893 |
| Total expenses | 154,487 | 165,565 | 426,167 | 537,737 |
| Expense waiver (Note 3) | -78,559 | -30,338 | -116,196 | -121,746 |
| Net expenses | 75,928 | 135,227 | 309,971 | 415,991 |
| Net income (loss) | ($6,637,563) | $2,662,100 | ($4,409,104) | ($670,550) |
| Net income (loss) per limited partnership share | ($8.61) | $1.87 | ($5.48) | ($2.20) |
| Net income (loss) per weighted average limited partnership share | ($8.14) | $2.78 | ($5.30) | ($0.67) |
| Weighted average limited partnership shares outstanding | 815,761 | 956,522 | 831,868 | 1,006,410 |
Condensed_Statements_of_Change
| Condensed Statements of Changes in Partners' Capital (USD $) | Total | General Partner | Limited Partners |
| Begining Balances at Dec. 31, 2013 | $56,897,171 | $0 | $56,897,171 |
| Net asset value, beginning of period at Dec. 31, 2013 | $59.89 | ' | ' |
| Addition of 300,000 partnership shares | 17,187,212 | 0 | 17,187,212 |
| Redemption of 300,000 partnership shares | -17,986,753 | 0 | -17,986,753 |
| Net loss | -4,409,104 | 0 | -4,409,104 |
| Ending Balances at Sep. 30, 2014 | $51,688,526 | $0 | $51,688,526 |
| Net asset value, end of period at Sep. 30, 2014 | $54.41 | ' | ' |
Condensed_Statements_of_Change1
| Condensed Statements of Changes in Partners' Capital (Parenthetical) | 9 Months Ended |
| Sep. 30, 2014 | |
| Addition of partnership units, units | 300,000 |
| Redemption of partnership units, units | 300,000 |
Condensed_Statements_of_Cash_F
| Condensed Statements of Cash Flows (USD $) | 9 Months Ended | |
| Sep. 30, 2014 | Sep. 30, 2013 | |
| Cash Flows from Operating Activities: | ' | ' |
| Net loss | ($4,409,104) | ($670,550) |
| Adjustments to reconcile net loss to net cash provided by (used in) operating activities: | ' | ' |
| (Increase) decrease in commodity futures trading account - cash and cash equivalents | -680,726 | 339,472 |
| Unrealized loss on open futures contracts | 4,057,801 | 4,114,522 |
| Decrease in dividends receivable | 56 | 744 |
| Decrease in receivable from General Partner | 69,700 | 17,700 |
| Decrease in other assets | 33,278 | 34,272 |
| Decrease in professional fees payable | -148,419 | -87,106 |
| Decrease in General Partner management fees payable | -2,779 | -6,817 |
| Decrease in brokerage commissions payable | -450 | -625 |
| Decrease in other liabilities | -654 | -83 |
| Net cash provided by (used in) operating activities | -1,081,297 | 3,741,529 |
| Cash Flows from Financing Activities: | ' | ' |
| Addition of partnership shares | 17,187,212 | 14,024,331 |
| Redemption of partnership shares | -17,986,753 | -27,010,014 |
| Net cash used in financing activities | -799,541 | -12,985,683 |
| Net Decrease in Cash and Cash Equivalents | -1,880,838 | -9,244,154 |
| Cash and Cash Equivalents, beginning of period | 52,193,157 | 56,400,613 |
| Cash and Cash Equivalents, end of period | $50,312,319 | $47,156,459 |
Organization_and_Business
| Organization and Business | 9 Months Ended |
| Sep. 30, 2014 | |
| Organization and Business | ' |
| NOTE 1 — ORGANIZATION AND BUSINESS | |
| The United States Gasoline Fund, LP (“UGA”) was organized as a limited partnership under the laws of the state of Delaware on April 13, 2007. UGA is a commodity pool that issues limited partnership shares (“shares”) that may be purchased and sold on the NYSE Arca, Inc. (the “NYSE Arca”). Prior to November 25, 2008, UGA’s shares traded on the American Stock Exchange (the “AMEX”). UGA will continue in perpetuity, unless terminated sooner upon the occurrence of one or more events as described in its Second Amended and Restated Agreement of Limited Partnership dated as of March 1, 2013 (the “LP Agreement”). The investment objective of UGA is for the daily changes in percentage terms of its shares’ per share net asset value (“NAV”) to reflect the daily changes in percentage terms of the price of gasoline (also known as reformulated gasoline blendstock for oxygen blending, or “RBOB”, for delivery to the New York harbor), as measured by the daily changes in the price of the futures contract for gasoline traded on the New York Mercantile Exchange (the “NYMEX”) that is the near month contract to expire, except when the near month contract is within two weeks of expiration, in which case the futures contract will be the next month contract to expire (the “Benchmark Futures Contract”), less UGA’s expenses. It is not the intent of UGA to be operated in a fashion such that the per share NAV will equal, in dollar terms, the spot price of gasoline or any particular futures contract based on gasoline. It is not the intent of UGA to be operated in a fashion such that its per share NAV will reflect the percentage change of the price of any particular futures contract as measured over a time period greater than one day. United States Commodity Funds LLC (“USCF”), the general partner of UGA, believes that it is not practical to manage the portfolio to achieve such an investment goal when investing in Futures Contracts (as defined below) and Other Gasoline-Related Investments (as defined below). UGA accomplishes its objective through investments in futures contracts for gasoline, crude oil, natural gas, heating oil and other petroleum-based fuels that are traded on the NYMEX, ICE Futures or other U.S. and foreign exchanges (collectively, “Futures Contracts”) and other gasoline-related investments such as cash-settled options on Futures Contracts, forward contracts for gasoline, cleared swap contracts and over-the-counter transactions that are based on the price of gasoline, crude oil and other petroleum-based fuels, Futures Contracts and indices based on the foregoing (collectively, “Other Gasoline-Related Investments”). As of September 30, 2014, UGA held 505 Futures Contracts for gasoline traded on the NYMEX and did not hold any Futures Contracts traded on ICE Futures. | |
| UGA commenced investment operations on February 26, 2008 and has a fiscal year ending on December 31. USCF is responsible for the management of UGA. USCF is a member of the National Futures Association (the “NFA”) and became a commodity pool operator registered with the Commodity Futures Trading Commission (the “CFTC”) effective December 1, 2005 and a swaps firm on August 8, 2013. USCF is also the general partner of the United States Oil Fund, LP (“USO”), the United States Natural Gas Fund, LP (“UNG”), the United States 12 Month Oil Fund, LP (“USL”) and the United States Diesel-Heating Oil Fund, LP (“UHN”), which listed their limited partnership shares on the AMEX under the ticker symbols “USO” on April 10, 2006, “UNG” on April 18, 2007, “USL” on December 6, 2007 and “UHN” on April 9, 2008, respectively. As a result of the acquisition of the AMEX by NYSE Euronext, each of USO’s, UNG’s, USL’s and UHN’s shares commenced trading on the NYSE Arca on November 25, 2008. USCF is also the general partner of the United States Short Oil Fund, LP (“DNO”), the United States 12 Month Natural Gas Fund, LP (“UNL”) and the United States Brent Oil Fund, LP (“BNO”), which listed their limited partnership shares on the NYSE Arca under the ticker symbols “DNO” on September 24, 2009, “UNL” on November 18, 2009 and “BNO” on June 2, 2010, respectively. USCF is also the sponsor of the United States Commodity Index Fund (“USCI”), the United States Copper Index Fund (“CPER”), the United States Agriculture Index Fund (“USAG”), and the United States Metals Index Fund (“USMI”), each a series of the United States Commodity Index Funds Trust. USCI, CPER, USAG and USMI listed their shares on the NYSE Arca under the ticker symbol “USCI” on August 10, 2010, “CPER” on November 15, 2011, “USAG” on April 13, 2012 and “USMI” on June 19, 2012, respectively. All funds listed previously are referred to collectively herein as the “Related Public Funds.” | |
| UGA issues shares to certain authorized purchasers (“Authorized Purchasers”) by offering baskets consisting of 50,000 shares (“Creation Baskets”) through ALPS Distributors, Inc., as the marketing agent (the “Marketing Agent”). The purchase price for a Creation Basket is based upon the NAV of a share calculated shortly after the close of the core trading session on the NYSE Arca on the day the order to create the basket is properly received. | |
| The applicable transaction fee paid by Authorized Purchasers is $350 to UGA for each order they place to create or redeem one or more baskets (“Redemption Baskets”). Shares may be purchased or sold on a nationally recognized securities exchange in smaller increments than a Creation Basket or Redemption Basket. Shares purchased or sold on a nationally recognized securities exchange are not purchased or sold at the per share NAV of UGA but rather at market prices quoted on such exchange. | |
| In November 2007, UGA initially registered 30,000,000 shares on Form S-1 with the U.S. Securities and Exchange Commission (the “SEC”). On February 26, 2008, UGA listed its shares on the AMEX under the ticker symbol “UGA”. On that day, UGA established its initial per share NAV by setting the price at $50.00 and issued 300,000 shares in exchange for $15,000,000. UGA also commenced investment operations on February 26, 2008 by purchasing Futures Contracts traded on the NYMEX based on gasoline. As a result of the acquisition of the AMEX by NYSE Euronext, UGA’s shares no longer trade on the AMEX and commenced trading on the NYSE Arca on November 25, 2008. As of September 30, 2014, UGA had registered a total of 80,000,000 shares. | |
| The accompanying unaudited condensed financial statements have been prepared in accordance with Rule 10-01 of Regulation S-X promulgated by the SEC and, therefore, do not include all information and footnote disclosure required under generally accepted accounting principles (“GAAP”) in the United States of America. The financial information included herein is unaudited; however, such financial information reflects all adjustments, consisting only of normal recurring adjustments, which are, in the opinion of USCF, necessary for the fair presentation of the condensed financial statements for the interim period. | |
Summary_of_Significant_Account
| Summary of Significant Accounting Policies | 9 Months Ended |
| Sep. 30, 2014 | |
| Summary of Significant Accounting Policies | ' |
| NOTE 2 — SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES | |
| Basis of Presentation | |
| The financial statements have been prepared in conformity with GAAP as detailed in the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification. UGA is an investment company and follows the accounting and reporting guidance in FASB Topic 946. | |
| 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. UGA earns interest on its assets denominated in U.S. dollars on deposit with the futures commission merchant at the 90-day Treasury bill rate. In addition, UGA earns income on funds held at the custodian or futures commission merchant at prevailing market rates earned on such investments. | |
| Brokerage Commissions | |
| Brokerage commissions on all open commodity futures contracts are accrued on a full-turn basis. | |
| Income Taxes | |
| UGA 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, UGA 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. UGA files an income tax return in the U.S. federal jurisdiction, and may file income tax returns in various U.S. states. UGA is not subject to income tax return examinations by major taxing authorities for years before 2010. 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 UGA recording a tax liability that reduces net assets. However, UGA’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. UGA 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 September 30, 2014. | |
| Creations and Redemptions | |
| Authorized Purchasers may purchase Creation Baskets or redeem Redemption Baskets only in blocks of 50,000 shares at a price equal to the NAV of the shares calculated shortly after the close of the core trading session on the NYSE Arca on the day the order is placed. | |
| UGA receives or pays the proceeds from shares 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 UGA’s condensed statements of financial condition as receivable for shares sold, and amounts payable to Authorized Purchasers upon redemption are reflected as payable for shares redeemed. | |
| Authorized Purchasers pay UGA a fee of $350 for each order placed to create one or more Creation Baskets or to redeem one or more Redemption Baskets. | |
| Partnership Capital and Allocation of Partnership Income and Losses | |
| Profit or loss shall be allocated among the partners of UGA in proportion to the number of shares 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 Share Net Asset Value | |
| UGA’s per share 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 shares outstanding. UGA 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 Share | |
| Net income (loss) per share is the difference between the per share NAV at the beginning of each period and at the end of each period. The weighted average number of shares outstanding was computed for purposes of disclosing net income (loss) per weighted average share. The weighted average shares are equal to the number of shares outstanding at the end of the period, adjusted proportionately for shares added and redeemed based on the amount of time the shares were outstanding during such period. There were no shares held by USCF at September 30, 2014. | |
| Offering Costs | |
| Offering costs incurred in connection with the registration of additional shares after the initial registration of shares are borne by UGA. 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. | |
Fees_Paid_By_The_Fund_And_Rela
| Fees Paid By The Fund And Related Party Transactions | 9 Months Ended |
| Sep. 30, 2014 | |
| Fees Paid By The Fund And Related Party Transactions | ' |
| NOTE 3 — FEES PAID BY THE FUND AND RELATED PARTY TRANSACTIONS | |
| USCF Management Fee | |
| Under the LP Agreement, USCF is responsible for investing the assets of UGA in accordance with the objectives and policies of UGA. In addition, USCF has arranged for one or more third parties to provide administrative, custody, accounting, transfer agency and other necessary services to UGA. For these services, UGA is contractually obligated to pay USCF a fee, which is paid monthly, equal to 0.60% per annum of average daily total net assets. | |
| Ongoing Registration Fees and Other Offering Expenses | |
| UGA pays all costs and expenses associated with the ongoing registration of its shares subsequent to the initial offering. These costs include registration or other fees paid to regulatory agencies in connection with the offer and sale of shares, and all legal, accounting, printing and other expenses associated with such offer and sale. For the nine months ended September 30, 2014 and 2013, UGA incurred $34,745 and $34,745, respectively, in registration fees and other offering expenses. | |
| Directors’ Fees and Expenses | |
| UGA is responsible for paying its portion of the directors’ and officers’ liability insurance for UGA and the Related Public Funds and the fees and expenses of the independent directors who also serve as audit committee members of UGA and the Related Public Funds. UGA shares the fees and expenses on a pro rata basis with each Related Public Fund, as described above, based on the relative assets of each Related Public Fund computed on a daily basis. These fees and expenses for the year ending December 31, 2014 are estimated to be a total of $560,625 for UGA and the Related Public Funds. | |
| Licensing Fees | |
| As discussed in Note 4 below, UGA entered into a licensing agreement with the NYMEX on April 10, 2006, as amended on October 20, 2011. Pursuant to the agreement, UGA and the Related Public Funds, other than BNO, USCI, CPER, USAG and USMI, pay a licensing fee that is equal to 0.015% on all net assets. During the nine months ended September 30, 2014 and 2013, UGA incurred $5,504 and $6,693, respectively, under this arrangement. | |
| Investor Tax Reporting Cost | |
| The fees and expenses associated with UGA’s audit expenses and tax accounting and reporting requirements are paid by UGA. These costs are estimated to be $135,000 for the year ending December 31, 2014. | |
| Other Expenses and Fees and Expense Waivers | |
| In addition to the fees described above, UGA pays all brokerage fees and other expenses in connection with the operation of UGA, excluding costs and expenses paid by USCF as outlined in Note 4 below. USCF has voluntarily agreed to pay certain expenses normally borne by UGA, to the extent that such expenses exceed 0.15% (15 basis points) of UGA’s NAV, on an annualized basis, through at least December 31, 2014. USCF has no obligation to continue such payments into subsequent periods. For the nine months ended September 30, 2014, USCF waived $116,196 of UGA’s expenses. This voluntary expense waiver is in addition to those amounts USCF is contractually obligated to pay as described in Note 4. | |
Contracts_and_Agreements
| Contracts and Agreements | 9 Months Ended | ||||||||
| Sep. 30, 2014 | |||||||||
| Contracts and Agreements | ' | ||||||||
| NOTE 4 — CONTRACTS AND AGREEMENTS | |||||||||
| UGA is party to a marketing agent agreement, dated as of February 15, 2008, as amended from time to time, with the Marketing Agent and USCF, whereby the Marketing Agent provides certain marketing services for UGA as outlined in the agreement. The fee of the Marketing Agent, which is borne by USCF, is equal to 0.06% on UGA’s assets up to $3 billion; and 0.04% on UGA’s assets in excess of $3 billion. In no event may the aggregate compensation paid to the Marketing Agent and any affiliate of USCF for distribution related services exceed 10% of the gross proceeds of UGA’s offering. | |||||||||
| The above fee does not include website construction and development, which are also borne by USCF. | |||||||||
| UGA is also party to a custodian agreement, dated January 16, 2008, as amended from time to time, with Brown Brothers Harriman & Co. (“BBH&Co.”) and USCF, whereby BBH&Co. holds investments on behalf of UGA. USCF pays the fees of the custodian, which are determined by the parties from time to time. In addition, UGA is party to an administrative agency agreement, dated February 7, 2008, as amended from time to time, with USCF and BBH&Co., whereby BBH&Co. acts as the administrative agent, transfer agent and registrar for UGA. USCF also pays the fees of BBH&Co. for its services under such agreement and such fees are determined by the parties from time to time. | |||||||||
| Currently, USCF pays BBH&Co. for its services, in the foregoing capacities, a minimum amount of $75,000 annually for its custody, fund accounting and fund administration services rendered to UGA and each of the Related Public Funds, as well as a $20,000 annual fee for its transfer agency services. In addition, USCF pays BBH&Co. an asset-based charge of (a) 0.06% for the first $500 million of the Related Public Funds’ combined net assets, (b) 0.0465% for the Related Public Funds’ combined net assets greater than $500 million but less than $1 billion, and (c) 0.035% once the Related Public Funds’ combined net assets exceed $1 billion. The annual minimum amount will not apply if the asset-based charge for all accounts in the aggregate exceeds $75,000. USCF also pays transaction fees ranging from $7 to $15 per transaction. | |||||||||
| On October 8, 2013, UGA entered into a brokerage agreement with RBC Capital Markets, LLC (“RBC Capital” or “RBC”) to serve as UGA’s futures commission merchant (“FCM”), effective October 10, 2013. Prior to October 10, 2013, the FCM was UBS Securities LLC (“UBS Securities”). The agreements require RBC Capital and UBS Securities to provide services to UGA in connection with the purchase and sale of Futures Contracts and Other Gasoline-Related Investments that may be purchased and sold by or through RBC Capital and/or UBS Securities for UGA’s account. In accordance with each agreement, RBC Capital and UBS Securities charge UGA commissions of approximately $7 to $15 per round-turn trade, including applicable exchange and NFA fees for Futures Contracts and options on Futures Contracts. Such fees include those incurred when purchasing Futures Contracts and options on Futures Contracts when UGA issues shares as a result of a Creation Basket, as well as fees incurred when selling Futures Contracts and options on Futures Contracts when UGA redeems shares as a result of a Redemption Basket. Such fees are also incurred when Futures Contracts and options on Futures Contracts are purchased or redeemed for the purpose of rebalancing the portfolio. UGA also incurs commissions to brokers for the purchase and sale of Futures Contracts, Other Gasoline-Related Investments or short-term obligations of the United States of two years or less (“Treasuries”). | |||||||||
| For the nine months ended | For the nine months ended | ||||||||
| September 30, 2014 | September 30, 2013 | ||||||||
| Total commissions accrued to brokers | $ | 25,698 | $ | 29,833 | |||||
| Commissions accrued as a result of rebalancing | $ | 24,830 | $ | 28,818 | |||||
| Percentage of commissions accrued as a result of rebalancing | 96.62 | % | 96.6 | % | |||||
| Commissions accrued as a result of creation and redemption activity | $ | 868 | $ | 1,015 | |||||
| Percentage of commissions accrued as a result of creation and redemption activity | 3.38 | % | 3.4 | % | |||||
| The decrease in the total commissions accrued to brokers for the nine months ended September 30, 2014, compared to the nine months ended September 30, 2013, was a result of decreased brokerage fees due to a lower number of futures contracts that were held and traded as a result of UGA’s reduced net assets. As an annualized percentage of average daily total net assets, the figure for the nine months ended September 30, 2014, represents approximately 0.07% of average daily total net assets. By comparison, the figure for the nine months ended September 30, 2013, represented approximately 0.07% of average daily total net assets. However, there can be no assurance that commission costs and portfolio turnover will not cause commission expenses to rise in future quarters. | |||||||||
| UGA and the NYMEX entered into a licensing agreement on April 10, 2006, as amended on October 20, 2011, whereby UGA was granted a non-exclusive license to use certain of the NYMEX’s settlement prices and service marks. Under the licensing agreement, UGA and the Related Public Funds, other than BNO, USCI, CPER, USAG and USMI, pay the NYMEX an asset-based fee for the license, the terms of which are described in Note 3. UGA expressly disclaims any association with the NYMEX or endorsement of UGA by the NYMEX and acknowledges that “NYMEX” and “New York Mercantile Exchange” are registered trademarks of the NYMEX. | |||||||||
Financial_Instruments_OffBalan
| Financial Instruments, Off-Balance Sheet Risks and Contingencies | 9 Months Ended |
| Sep. 30, 2014 | |
| Financial Instruments, Off-Balance Sheet Risks and Contingencies | ' |
| NOTE 5 — FINANCIAL INSTRUMENTS, OFF-BALANCE SHEET RISKS AND CONTINGENCIES | |
| UGA engages in the trading of futures contracts, options on futures contracts and cleared swaps (collectively, “derivatives”). UGA 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. | |
| UGA may enter into futures contracts, options on futures contracts and cleared swaps 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. Cleared swaps are over-the-counter agreements that are eligible to be cleared by a clearinghouse, e.g., ICE Clear Europe, but which are not traded on an exchange. A cleared swap is created when the parties to an off-exchange over-the-counter swap transaction agree to extinguish their over-the-counter contract and replace it with a cleared swap. Cleared swaps are intended to provide the efficiencies and benefits that centralized clearing on an exchange offers to traders of futures contracts, including credit risk intermediation and the ability to offset positions initiated with different counterparties. | |
| 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, options on 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 UGA 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. Buying and selling options on futures contracts exposes investors to the risks of purchasing or selling futures contracts. | |
| All of the futures contracts held by UGA were exchange-traded through September 30, 2014. 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 UGA were to enter into non-exchange traded contracts, it would be subject 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. UGA 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, UGA bears the risk of financial failure by the clearing broker. | |
| UGA’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 UGA’s assets posted with that futures commission merchant; however, the majority of UGA’s assets are held in investments in Treasuries, cash and/or cash equivalents with UGA’s custodian and would not be impacted by the insolvency of a futures commission merchant. The failure or insolvency of UGA’s custodian, however, could result in a substantial loss of UGA’s assets. | |
| USCF invests a portion of UGA’s cash in money market funds that seek to maintain a stable per share NAV. UGA is exposed to any risk of loss associated with an investment in such money market funds. As of September 30, 2014 and December 31, 2013, UGA held investments in money market funds in the amounts of $30,994,983 and $38,494,983, respectively. UGA 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 September 30, 2014 and December 31, 2013, UGA held cash deposits and investments in Treasuries in the amounts of $22,051,546 and $15,751,658, respectively, with the custodian and futures commission merchant. Some or all of these amounts may be subject to loss should UGA’s custodian and/or futures commission merchant cease operations. | |
| For derivatives, risks arise from changes in the market value of the contracts. Theoretically, UGA 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, UGA 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. | |
| UGA’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, UGA has a policy of requiring review of the credit standing of each counterparty with which it conducts business. | |
| The financial instruments held by UGA are reported in its condensed 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_Highlights
| Financial Highlights | 9 Months Ended | ||||||||
| Sep. 30, 2014 | |||||||||
| Financial Highlights | ' | ||||||||
| NOTE 6 — FINANCIAL HIGHLIGHTS | |||||||||
| The following table presents per share performance data and other supplemental financial data for the nine months ended September 30, 2014 and 2013 for the shareholders. This information has been derived from information presented in the condensed financial statements. | |||||||||
| For the nine months ended | For the nine months ended | ||||||||
| September 30, 2014 | September 30, 2013 | ||||||||
| (Unaudited) | (Unaudited) | ||||||||
| Per Share Operating Performance: | |||||||||
| Net asset value, beginning of period | $ | 59.89 | $ | 58.39 | |||||
| Total loss | -5.11 | -1.79 | |||||||
| Net expenses | -0.37 | -0.41 | |||||||
| Net decrease in net asset value | -5.48 | -2.2 | |||||||
| Net asset value, end of period | $ | 54.41 | $ | 56.19 | |||||
| Total Return | -9.15 | % | -3.77 | % | |||||
| Ratios to Average Net Assets | |||||||||
| Total loss | -8.36 | % | -0.43 | % | |||||
| Management fees* | 0.6 | % | 0.6 | % | |||||
| Total expenses excluding management fees* | 0.56 | % | 0.61 | % | |||||
| Expenses waived* | -0.32 | % | -0.27 | % | |||||
| Net expenses excluding management fees* | 0.24 | % | 0.33 | % | |||||
| Net loss | -8.99 | % | -1.12 | % | |||||
| * Annualized | |||||||||
| Total returns are calculated based on the change in value during the period. An individual shareholder’s total return and ratio may vary from the above total returns and ratios based on the timing of contributions to and withdrawals from UGA. | |||||||||
Fair_Value_of_Financial_Instru
| Fair Value of Financial Instruments | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Fair Value of Financial Instruments | ' | |||||||||||||||
| NOTE 7 — FAIR VALUE OF FINANCIAL INSTRUMENTS | ||||||||||||||||
| UGA values its investments in accordance with Accounting Standards Codification 820 – Fair Value Measurements and Disclosures (“ASC 820”). ASC 820 defines fair value, establishes a framework for measuring fair value in generally accepted accounting principles, and expands disclosures about fair value measurement. The changes to past practice resulting from the application of ASC 820 relate to the definition of fair value, the methods used to measure fair value, and the expanded disclosures about fair value measurement. ASC 820 establishes a fair value hierarchy that distinguishes between: (1) market participant assumptions developed based on market data obtained from sources independent of UGA (observable inputs) and (2) UGA’s own assumptions about market participant assumptions developed based on the best information available under the circumstances (unobservable inputs). The three levels defined by the ASC 820 hierarchy are as follows: | ||||||||||||||||
| Level I – Quoted prices (unadjusted) in active markets for identical assets or liabilities that the reporting entity has the ability to access at the measurement date. | ||||||||||||||||
| Level II – Inputs other than quoted prices included within Level I that are observable for the asset or liability, either directly or indirectly. Level II assets include the following: quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, inputs other than quoted prices that are observable for the asset or liability, and inputs that are derived principally from or corroborated by observable market data by correlation or other means (market-corroborated inputs). | ||||||||||||||||
| Level III – Unobservable pricing input at the measurement date for the asset or liability. Unobservable inputs shall be used to measure fair value to the extent that observable inputs are not available. | ||||||||||||||||
| In some instances, the inputs used to measure fair value might fall within different levels of the fair value hierarchy. The level in the fair value hierarchy within which the fair value measurement in its entirety falls shall be determined based on the lowest input level that is significant to the fair value measurement in its entirety. | ||||||||||||||||
| The following table summarizes the valuation of UGA’s securities at September 30, 2014 using the fair value hierarchy: | ||||||||||||||||
| At September 30, 2014 | Total | Level I | Level II | Level III | ||||||||||||
| Short-Term Investments | $ | 36,994,331 | $ | 36,994,331 | $ | — | $ | — | ||||||||
| Exchange-Traded Futures Contracts | ||||||||||||||||
| United States Contracts | -1,459,248 | -1,459,248 | — | — | ||||||||||||
| During the nine months ended September 30, 2014, there were no transfers between Level I and Level II. | ||||||||||||||||
| The following table summarizes the valuation of UGA’s securities at December 31, 2013 using the fair value hierarchy: | ||||||||||||||||
| At December 31, 2013 | Total | Level I | Level II | Level III | ||||||||||||
| Short-Term Investments | $ | 48,493,330 | $ | 48,493,330 | $ | — | $ | — | ||||||||
| Exchange-Traded Futures Contracts | ||||||||||||||||
| United States Contracts | 2,598,553 | 2,598,553 | — | — | ||||||||||||
| During the year ended December 31, 2013, there were no transfers between Level I and Level II. | ||||||||||||||||
| Effective January 1, 2009, UGA adopted the provisions of Accounting Standards Codification 815—Derivatives and Hedging, which require presentation of qualitative disclosures about objectives and strategies for using derivatives, quantitative disclosures about fair value amounts and gains and losses on derivatives. | ||||||||||||||||
| Fair Value of Derivative Instruments | ||||||||||||||||
| Condensed | ||||||||||||||||
| Derivatives not | Statements of Financial | Fair Value | Fair Value | |||||||||||||
| Accounted for as Hedging Instruments | Condition Location | At September 30, 2014 | At December 31, 2013 | |||||||||||||
| Futures - Commodity Contracts | Assets | $ | -1,459,248 | $ | 2,598,553 | |||||||||||
| The Effect of Derivative Instruments on the Condensed Statements of Operations | ||||||||||||||||
| For the nine months ended | For the nine months ended | |||||||||||||||
| September 30, 2014 | September 30, 2013 | |||||||||||||||
| Change in | Change in | |||||||||||||||
| Location of | Realized | Unrealized | Realized | Unrealized | ||||||||||||
| Derivatives not | Gain or (Loss) | Loss on | Loss on | Gain on | Loss on | |||||||||||
| Accounted for | on Derivatives | Derivatives | Derivatives | Derivatives | Derivatives | |||||||||||
| as Hedging | Recognized | Recognized in | Recognized in | Recognized in | Recognized in | |||||||||||
| Instruments | in Income | Income | Income | Income | Income | |||||||||||
| Futures – Commodity Contracts | Realized gain (loss) on closed positions | $ | -54,730 | $ | 3,844,332 | |||||||||||
| Change in unrealized loss on open positions | $ | -4,057,801 | $ | -4,114,522 | ||||||||||||
Subsequent_Events
| Subsequent Events | 9 Months Ended |
| Sep. 30, 2014 | |
| Subsequent Events | ' |
| NOTE 8 — SUBSEQUENT EVENTS | |
| UGA has performed an evaluation of subsequent events through the date the condensed financial statements were issued. This evaluation did not result in any subsequent events that necessitated disclosures and/or adjustments. | |
Summary_of_Significant_Account1
| Summary of Significant Accounting Policies (Policies) | 9 Months Ended |
| Sep. 30, 2014 | |
| Basis of Presentation | ' |
| Basis of Presentation | |
| The financial statements have been prepared in conformity with GAAP as detailed in the Financial Accounting Standards Board’s (“FASB”) Accounting Standards Codification. UGA is an investment company and follows the accounting and reporting guidance in FASB Topic 946. | |
| Revenue Recognition | ' |
| 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. UGA earns interest on its assets denominated in U.S. dollars on deposit with the futures commission merchant at the 90-day Treasury bill rate. In addition, UGA earns income on funds held at the custodian or futures commission merchant at prevailing market rates earned on such investments. | |
| Brokerage Commissions | ' |
| Brokerage Commissions | |
| Brokerage commissions on all open commodity futures contracts are accrued on a full-turn basis. | |
| Income Taxes | ' |
| Income Taxes | |
| UGA 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, UGA 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. UGA files an income tax return in the U.S. federal jurisdiction, and may file income tax returns in various U.S. states. UGA is not subject to income tax return examinations by major taxing authorities for years before 2010. 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 UGA recording a tax liability that reduces net assets. However, UGA’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. UGA 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 September 30, 2014. | |
| Creations and Redemptions | ' |
| Creations and Redemptions | |
| Authorized Purchasers may purchase Creation Baskets or redeem Redemption Baskets only in blocks of 50,000 shares at a price equal to the NAV of the shares calculated shortly after the close of the core trading session on the NYSE Arca on the day the order is placed. | |
| UGA receives or pays the proceeds from shares 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 UGA’s condensed statements of financial condition as receivable for shares sold, and amounts payable to Authorized Purchasers upon redemption are reflected as payable for shares redeemed. | |
| Authorized Purchasers pay UGA a fee of $350 for each order placed to create one or more Creation Baskets or to redeem one or more Redemption Baskets. | |
| Partnership Capital and Allocation of Partnership Income and Losses | ' |
| Partnership Capital and Allocation of Partnership Income and Losses | |
| Profit or loss shall be allocated among the partners of UGA in proportion to the number of shares 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 Share Net Asset Value | ' |
| Calculation of Per Share Net Asset Value | |
| UGA’s per share 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 shares outstanding. UGA 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 Share | ' |
| Net Income (Loss) Per Share | |
| Net income (loss) per share is the difference between the per share NAV at the beginning of each period and at the end of each period. The weighted average number of shares outstanding was computed for purposes of disclosing net income (loss) per weighted average share. The weighted average shares are equal to the number of shares outstanding at the end of the period, adjusted proportionately for shares added and redeemed based on the amount of time the shares were outstanding during such period. There were no shares held by USCF at September 30, 2014. | |
| Offering Costs | ' |
| Offering Costs | |
| Offering costs incurred in connection with the registration of additional shares after the initial registration of shares are borne by UGA. 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 | |
| Cash equivalents include money market funds and overnight deposits or time deposits with original maturity dates of six months or less. | |
| Reclassification | ' |
| Reclassification | |
| Certain amounts in the accompanying condensed financial statements were reclassified to conform to the current presentation. | |
| Use of Estimates | ' |
| 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. | |
Contracts_and_Agreements_Table
| Contracts and Agreements (Tables) | 9 Months Ended | ||||||||
| Sep. 30, 2014 | |||||||||
| Brokerage Commissions | ' | ||||||||
| UGA also incurs commissions to brokers for the purchase and sale of Futures Contracts, Other Gasoline-Related Investments or short-term obligations of the United States of two years or less (“Treasuries”). | |||||||||
| For the nine months ended | For the nine months ended | ||||||||
| September 30, 2014 | September 30, 2013 | ||||||||
| Total commissions accrued to brokers | $ | 25,698 | $ | 29,833 | |||||
| Commissions accrued as a result of rebalancing | $ | 24,830 | $ | 28,818 | |||||
| Percentage of commissions accrued as a result of rebalancing | 96.62 | % | 96.6 | % | |||||
| Commissions accrued as a result of creation and redemption activity | $ | 868 | $ | 1,015 | |||||
| Percentage of commissions accrued as a result of creation and redemption activity | 3.38 | % | 3.4 | % | |||||
Financial_Highlights_Tables
| Financial Highlights (Tables) | 9 Months Ended | ||||||||
| Sep. 30, 2014 | |||||||||
| Per Unit Performance Data and Other Supplemental Financial Data | ' | ||||||||
| The following table presents per share performance data and other supplemental financial data for the nine months ended September 30, 2014 and 2013 for the shareholders. This information has been derived from information presented in the condensed financial statements. | |||||||||
| For the nine months ended | For the nine months ended | ||||||||
| September 30, 2014 | September 30, 2013 | ||||||||
| (Unaudited) | (Unaudited) | ||||||||
| Per Share Operating Performance: | |||||||||
| Net asset value, beginning of period | $ | 59.89 | $ | 58.39 | |||||
| Total loss | -5.11 | -1.79 | |||||||
| Net expenses | -0.37 | -0.41 | |||||||
| Net decrease in net asset value | -5.48 | -2.2 | |||||||
| Net asset value, end of period | $ | 54.41 | $ | 56.19 | |||||
| Total Return | -9.15 | % | -3.77 | % | |||||
| Ratios to Average Net Assets | |||||||||
| Total loss | -8.36 | % | -0.43 | % | |||||
| Management fees* | 0.6 | % | 0.6 | % | |||||
| Total expenses excluding management fees* | 0.56 | % | 0.61 | % | |||||
| Expenses waived* | -0.32 | % | -0.27 | % | |||||
| Net expenses excluding management fees* | 0.24 | % | 0.33 | % | |||||
| Net loss | -8.99 | % | -1.12 | % | |||||
| * Annualized | |||||||||
Fair_Value_of_Financial_Instru1
| Fair Value of Financial Instruments (Tables) | 9 Months Ended | |||||||||||||||
| Sep. 30, 2014 | ||||||||||||||||
| Valuation of Securities Using Fair Value Hierarchy | ' | |||||||||||||||
| The following table summarizes the valuation of UGA’s securities at September 30, 2014 using the fair value hierarchy: | ||||||||||||||||
| At September 30, 2014 | Total | Level I | Level II | Level III | ||||||||||||
| Short-Term Investments | $ | 36,994,331 | $ | 36,994,331 | $ | — | $ | — | ||||||||
| Exchange-Traded Futures Contracts | ||||||||||||||||
| United States Contracts | -1,459,248 | -1,459,248 | — | — | ||||||||||||
| During the nine months ended September 30, 2014, there were no transfers between Level I and Level II. | ||||||||||||||||
| The following table summarizes the valuation of UGA’s securities at December 31, 2013 using the fair value hierarchy: | ||||||||||||||||
| At December 31, 2013 | Total | Level I | Level II | Level III | ||||||||||||
| Short-Term Investments | $ | 48,493,330 | $ | 48,493,330 | $ | — | $ | — | ||||||||
| Exchange-Traded Futures Contracts | ||||||||||||||||
| United States Contracts | 2,598,553 | 2,598,553 | — | — | ||||||||||||
| During the year ended December 31, 2013, there were no transfers between Level I and Level II. | ||||||||||||||||
| Fair Value of Derivative Instruments | ' | |||||||||||||||
| Fair Value of Derivative Instruments | ||||||||||||||||
| Condensed | ||||||||||||||||
| Derivatives not | Statements of Financial | Fair Value | Fair Value | |||||||||||||
| Accounted for as Hedging Instruments | Condition Location | At September 30, 2014 | At December 31, 2013 | |||||||||||||
| Futures - Commodity Contracts | Assets | $ | -1,459,248 | $ | 2,598,553 | |||||||||||
| Effect of Derivative Instruments on Condensed Statements of Operations | ' | |||||||||||||||
| The Effect of Derivative Instruments on the Condensed Statements of Operations | ||||||||||||||||
| For the nine months ended | For the nine months ended | |||||||||||||||
| September 30, 2014 | September 30, 2013 | |||||||||||||||
| Change in | Change in | |||||||||||||||
| Location of | Realized | Unrealized | Realized | Unrealized | ||||||||||||
| Derivatives not | Gain or (Loss) | Loss on | Loss on | Gain on | Loss on | |||||||||||
| Accounted for | on Derivatives | Derivatives | Derivatives | Derivatives | Derivatives | |||||||||||
| as Hedging | Recognized | Recognized in | Recognized in | Recognized in | Recognized in | |||||||||||
| Instruments | in Income | Income | Income | Income | Income | |||||||||||
| Futures – Commodity Contracts | Realized gain (loss) on closed positions | $ | -54,730 | $ | 3,844,332 | |||||||||||
| Change in unrealized loss on open positions | $ | -4,057,801 | $ | -4,114,522 | ||||||||||||
Organization_and_Business_Addi
| Organization and Business - Additional Information (Detail) (USD $) | 0 Months Ended | 9 Months Ended | |||||
| Feb. 26, 2008 | Nov. 30, 2007 | Sep. 30, 2014 | Dec. 31, 2013 | Sep. 30, 2013 | Dec. 31, 2012 | ||
| Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items] | ' | ' | ' | ' | ' | ' | |
| Fee paid by Authorized Purchasers for each order placed to create one or more Creation Baskets or to redeem one or more baskets | ' | ' | $350 | ' | ' | ' | |
| Number of initially registered units on Form S-1 with the U.S. Securities and Exchange Commission | ' | 30,000,000 | ' | ' | ' | ' | |
| Net asset value per unit | $50 | ' | $54.41 | $59.89 | $56.19 | $58.39 | |
| Number of units issued | 300,000 | ' | ' | ' | ' | ' | |
| Value of units issued | $15,000,000 | ' | ' | ' | ' | ' | |
| Number of registered units | ' | ' | 80,000,000 | ' | ' | ' | |
| Creation Baskets | ' | ' | ' | ' | ' | ' | |
| Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items] | ' | ' | ' | ' | ' | ' | |
| Number of units per basket | ' | ' | 50,000 | ' | ' | ' | |
| Open Cleared Swap and Futures Contracts | Open Futures Contracts, Long | United States | NYMEX RBOB Gasoline Futures RB November 2014 contracts, expiring October 2014 | ' | ' | ' | ' | ' | ' | |
| Organization, Consolidation and Presentation of Financial Statements Disclosure [Line Items] | ' | ' | ' | ' | ' | ' | |
| Number of contracts | ' | ' | 505 | [1] | ' | ' | ' |
| [1] | Collateral amounted to $2,734,210 on open future contracts. | ||||||
Summary_of_Significant_Account2
| Summary of Significant Accounting Policies - Additional Information (Detail) (USD $) | 9 Months Ended |
| Sep. 30, 2014 | |
| Significant Accounting Policies [Line Items] | ' |
| Fee paid by Authorized Purchasers for each order placed to create one or more Creation Baskets or to redeem one or more baskets | $350 |
| Creation Baskets | ' |
| Significant Accounting Policies [Line Items] | ' |
| Number of units per basket | 50,000 |
| Redemption Baskets | ' |
| Significant Accounting Policies [Line Items] | ' |
| Number of units per basket | 50,000 |
Fees_Paid_By_The_Fund_And_Rela1
| Fees Paid By The Fund And Related Party Transactions - Additional Information (Detail) (USD $) | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | |
| Fees Paid and Related Party Transactions [Line Items] | ' | ' | ' | ' |
| USCF Management Fee | ' | ' | 'UGA is contractually obligated to pay USCF a fee, which is paid monthly, equal to 0.60% per annum of average daily total net assets. | ' |
| Percentage of average daily net assets | 0.60% | ' | 0.60% | ' |
| Ongoing registration fees and other offering expenses | ' | ' | $34,745 | $34,745 |
| Licensing fee incurred | ' | ' | 5,504 | 6,693 |
| Estimated investor tax reporting cost | ' | ' | 135,000 | ' |
| Expense waiver | 78,559 | 30,338 | 116,196 | 121,746 |
| Maximum | ' | ' | ' | ' |
| Fees Paid and Related Party Transactions [Line Items] | ' | ' | ' | ' |
| Costs and expenses annual limit for reimbursement | ' | ' | 0.15% | ' |
| UGA and the Related Public Funds | ' | ' | ' | ' |
| Fees Paid and Related Party Transactions [Line Items] | ' | ' | ' | ' |
| Estimated directors' fees and expenses | ' | ' | $560,625 | ' |
| Licensing Agreements [Member] | On and after October 20, 2011 | ' | ' | ' | ' |
| Fees Paid and Related Party Transactions [Line Items] | ' | ' | ' | ' |
| Assets basis for determining fee percentage | ' | ' | 'on all net assets | ' |
| Costs and expenses annual limit for reimbursement | ' | ' | 0.02% | ' |
Contracts_and_Agreements_Broke
| Contracts and Agreements (Brokerage Commissions) (Detail) (USD $) | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | |
| Long Duration Contracts Assumptions By Product And Guarantee [Line Items] | ' | ' | ' | ' |
| Brokerage commissions | $8,929 | $9,866 | $25,698 | $29,833 |
| Brokerage commissions as a percentage of average daily net assets | 0.60% | ' | 0.60% | ' |
| Rebalancing Investments Transaction [Member] | ' | ' | ' | ' |
| Long Duration Contracts Assumptions By Product And Guarantee [Line Items] | ' | ' | ' | ' |
| Brokerage commissions | ' | ' | 24,830 | 28,818 |
| Brokerage commissions as a percentage of average daily net assets | 96.62% | 96.60% | 96.62% | 96.60% |
| Creation And Redemption Activity [Member] | ' | ' | ' | ' |
| Long Duration Contracts Assumptions By Product And Guarantee [Line Items] | ' | ' | ' | ' |
| Brokerage commissions | ' | ' | $868 | $1,015 |
| Brokerage commissions as a percentage of average daily net assets | 3.38% | 3.40% | 3.38% | 3.40% |
Contracts_and_Agreements_Addit
| Contracts and Agreements - Additional Information (Detail) (USD $) | 9 Months Ended | |
| Sep. 30, 2014 | Sep. 30, 2013 | |
| Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] | ' | ' |
| Annual transfer agency services fee | $20,000 | ' |
| Annualized percentage of average daily total net assets | 0.07% | 0.07% |
| Maximum | ' | ' |
| Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] | ' | ' |
| Transaction fees per transaction | 15 | ' |
| Commissions per round-turn trade, including applicable exchange and NFA fees for Oil Futures Contracts and options on Oil Futures Contracts | 15 | ' |
| Minimum | ' | ' |
| Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] | ' | ' |
| Annual Fee for custody, fund accounting and fund administration services | 75,000 | ' |
| Transaction fees per transaction | 7 | ' |
| Commissions per round-turn trade, including applicable exchange and NFA fees for Oil Futures Contracts and options on Oil Futures Contracts | 7 | ' |
| First $500 million of the Related Public Funds' combined net assets | ' | ' |
| Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] | ' | ' |
| Fee percentage | 0.06% | ' |
| First $500 million of the Related Public Funds' combined net assets | Maximum | ' | ' |
| Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] | ' | ' |
| Base amount for determining fee percentage | 500,000,000 | ' |
| Related Public Funds' combined net assets greater than $500 million but less than $1 billion | ' | ' |
| Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] | ' | ' |
| Fee percentage | 0.05% | ' |
| Related Public Funds' combined net assets greater than $500 million but less than $1 billion | Maximum | ' | ' |
| Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] | ' | ' |
| Base amount for determining fee percentage | 1,000,000,000 | ' |
| Related Public Funds' combined net assets greater than $500 million but less than $1 billion | Minimum | ' | ' |
| Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] | ' | ' |
| Base amount for determining fee percentage | 500,000,000 | ' |
| Related Public Funds' combined net assets exceed $1 billion | ' | ' |
| Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] | ' | ' |
| Fee percentage | 0.04% | ' |
| Related Public Funds' combined net assets exceed $1 billion | Minimum | ' | ' |
| Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] | ' | ' |
| Base amount for determining fee percentage | 1,000,000,000 | ' |
| Marketing Agreement [Member] | Assets up to $3 billion | ' | ' |
| Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] | ' | ' |
| Fee percentage | 0.06% | ' |
| Marketing Agreement [Member] | Assets up to $3 billion | Maximum | ' | ' |
| Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] | ' | ' |
| Base amount for determining fee percentage | 3,000,000,000 | ' |
| Marketing Agreement [Member] | Assets in excess of $3 billion | ' | ' |
| Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] | ' | ' |
| Fee percentage | 0.04% | ' |
| Marketing Agreement [Member] | Assets in excess of $3 billion | Minimum | ' | ' |
| Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] | ' | ' |
| Base amount for determining fee percentage | $3,000,000,000 | ' |
Financial_Instruments_OffBalan1
| Financial Instruments, Off-Balance Sheet Risks and Contingencies - Additional Information (Detail) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| Cash investments in money market funds | $30,994,983 | $38,494,983 |
| Deposits in domestic and foreign financial institutions | $22,051,546 | $15,751,658 |
Financial_Highlights_Per_Share
| Financial Highlights (Per Share Performance Data and Other Supplemental Financial Data) (Detail) (USD $) | 9 Months Ended | ||||
| Sep. 30, 2014 | Sep. 30, 2013 | Feb. 26, 2008 | |||
| Per Share Operating Performance: | ' | ' | ' | ||
| Net asset value, beginning of period | $59.89 | $58.39 | $50 | ||
| Total loss | ($5.11) | ($1.79) | ' | ||
| Net expenses | ($0.37) | ($0.41) | ' | ||
| Net decrease in net asset value | ($5.48) | ($2.20) | ' | ||
| Net asset value, end of period | $54.41 | $56.19 | $50 | ||
| Total Return | -9.15% | -3.77% | ' | ||
| Ratios to Average Net Assets | ' | ' | ' | ||
| Total loss | -8.36% | -0.43% | ' | ||
| Management fees | 0.60% | [1] | 0.60% | [1] | ' |
| Total expenses excluding management fees | 0.56% | [1] | 0.61% | [1] | ' |
| Expenses waived | -0.32% | [1] | -0.27% | [1] | ' |
| Net expenses excluding management fees | 0.24% | [1] | 0.33% | [1] | ' |
| Net loss | -8.99% | -1.12% | ' | ||
| [1] | Annualized | ||||
Fair_Value_of_Financial_Instru2
| Fair Value of Financial Instruments (Valuation of Securities Using Fair Value Hierarchy) (Detail) (USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| Short-Term Investments | ' | ' |
| Schedule of Trading Securities and Other Trading Assets [Line Items] | ' | ' |
| Securities, fair value | $36,994,331 | $48,493,330 |
| Exchange-Traded Futures Contracts | United States | ' | ' |
| Schedule of Trading Securities and Other Trading Assets [Line Items] | ' | ' |
| Securities, fair value | -1,459,248 | 2,598,553 |
| Fair Value, Inputs, Level 1 | Short-Term Investments | ' | ' |
| Schedule of Trading Securities and Other Trading Assets [Line Items] | ' | ' |
| Securities, fair value | 36,994,331 | 48,493,330 |
| Fair Value, Inputs, Level 1 | Exchange-Traded Futures Contracts | United States | ' | ' |
| Schedule of Trading Securities and Other Trading Assets [Line Items] | ' | ' |
| Securities, fair value | ($1,459,248) | $2,598,553 |
Fair_Value_of_Financial_Instru3
| Fair Value of Financial Instruments (Fair Value of Derivative Instruments) (Detail) (Commodity Contracts, Futures, Assets, USD $) | Sep. 30, 2014 | Dec. 31, 2013 |
| Commodity Contracts | Futures | Assets | ' | ' |
| Derivatives, Fair Value [Line Items] | ' | ' |
| Derivatives not Accounted for as Hedging Instruments | ($1,459,248) | $2,598,553 |
Fair_Value_of_Financial_Instru4
| Fair Value of Financial Instruments (Effect of Derivative Instruments on Condensed Statements of Operations) (Detail) (USD $) | 3 Months Ended | 9 Months Ended | ||
| Sep. 30, 2014 | Sep. 30, 2013 | Sep. 30, 2014 | Sep. 30, 2013 | |
| Derivative Instruments, Gain (Loss) [Line Items] | ' | ' | ' | ' |
| Realized Gain or (Loss) on Derivatives Recognized in Income | ($5,067,119) | $952,430 | ($54,730) | $3,844,332 |
| Change in Unrealized Gain or (Loss) on Derivatives Recognized in Income | ' | ' | -4,057,801 | -4,114,522 |
| Commodity Contracts | Futures | Realized gain (loss) on closed positions | ' | ' | ' | ' |
| Derivative Instruments, Gain (Loss) [Line Items] | ' | ' | ' | ' |
| Realized Gain or (Loss) on Derivatives Recognized in Income | ' | ' | -54,730 | 3,844,332 |
| Commodity Contracts | Futures | Change in unrealized gain (loss) on open positions | ' | ' | ' | ' |
| Derivative Instruments, Gain (Loss) [Line Items] | ' | ' | ' | ' |
| Change in Unrealized Gain or (Loss) on Derivatives Recognized in Income | ' | ' | ($4,057,801) | ($4,114,522) |