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Contracts and Agreements (Additional Information) (Details) (USD $) | 3 Months Ended
--- | ---
Mar. 31, 2014 | Mar. 31, 2013
Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] |  |
Annual Fee for transfer agency services | $ 20,000 |
Brokerage commissions | 1,400 | 3,982
Ratio of expense to Average Net Assets | 0.01% | 0.01%
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 transfer agency 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 |
Re balancing Investments Transaction |  |
Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] |  |
Brokerage commissions | 999 | 1,852
Floor Brokerage Exchange And Clearance Fees Percentage | 71.36% | 46.51%
Trades Necessitated By Creation And Redemption Activity |  |
Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] |  |
Brokerage commissions | 401 | 2,130
Floor Brokerage Exchange And Clearance Fees Percentage | 28.64% | 53.49%
First $500 million of USL's, USOF's, USNG's, UGA's, USDHO's, USSO's, US12NG's, USBO's, USCI's, CPER's, USAG's and USMI's combined net assets |  |
Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] |  |
Fee percentage | 0.06% |
First $500 million of USL's, USOF's, USNG's, UGA's, USDHO's, USSO's, US12NG's, USBO's, USCI's, CPER's, USAG's and USMI's combined net assets | Maximum |  |
Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] |  |
Base amount for determining fee percentage | 500,000,000 |
USL's, USOF's, USNG's, UGA's, USDHO's, USSO's, US12NG's, USBO's, USCI's, CPER's, USAG's and USMI's combined net assets greater than $500 million but less than $1 billion |  |
Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] |  |
Fee percentage | 0.0465% |
USL's, USOF's, USNG's, UGA's, USDHO's, USSO's, US12NG's, USBO's, USCI's, CPER's, USAG's and USMI's 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 |
USL's, USOF's, USNG's, UGA's, USDHO's, USSO's, US12NG's, USBO's, USCI's, CPER's, USAG's and USMI's 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 |
USL's, USOF's, USNG's, UGA's, USDHO's, USSO's, US12NG's, USBO's, USCI's, CPER's, USAG's and USMI's combined net assets exceed $1 billion |  |
Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] |  |
Fee percentage | 0.035% |
USL's, USOF's, USNG's, UGA's, USDHO's, USSO's, US12NG's, USBO's, USCI's, CPER's, USAG's and USMI's combined net assets exceed $1 billion | Maximum |  |
Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] |  |
Base amount for determining fee percentage | 1,000,000,000 |
Marketing Agreement | USL's assets up to $3 billion |  |
Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] |  |
Fee percentage | 0.06% |
Marketing Agreement | USL's 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 | USL's assets in excess of $3 billion |  |
Long-Duration Contracts, Assumptions by Product and Guarantee [Line Items] |  |
Fee percentage | 0.04% |
Marketing Agreement | USL's 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 |

X
- Definition The amount of expense during the period for floor brokerage fees paid to other broker-dealers to execute trades on their behalf, stock exchange fees, order flow fees, and clearance fees. + References No definition available. + Details
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- Definition Fees paid to an agent employed by a corporation or mutual fund to maintain shareholder records, including purchases, sales, and account balances. Also includes custodian fees incurred during an accounting period from an agent, bank, trust company, or other organization that holds and safeguards an individual's, mutual fund's, or investment company's assets for them. These fees will be billed back to the client and are a component of noninterest expense. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.14) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 + Details
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- Definition Commissions Paid + References No definition available. + Details
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- Definition The percentage of amount of expense during the period for floor brokerage fees paid to other broker-dealers to execute trades on their behalf, stock exchange fees, order flow fees, and clearance fees. + References No definition available. + Details
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- Definition Transaction Fees Paid. + References No definition available. + Details
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