XML 44 R26.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Fees Paid by the Fund and Related Party Transactions (Additional Information) (Details) - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Fees Paid and Related Party Transactions [Line Items] |  |  |
USCF Management Fee | USL 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 | $ 0 | $ 1,350 | $ 82,385
Licensing fee incurred | 10,849 | 7,910 | 12,774
Estimated investor tax reporting cost | 100,000 | 169,000 | 150,000
Estimated directors' fees and expenses | 9,808 | 15,649 | 19,340
USL and the Related Public Funds, other than USCI, USAG, CPER and USMI |  |  |
Fees Paid and Related Party Transactions [Line Items] |  |  |
Estimated directors' fees and expenses | $ 569,303 | $ 567,863 | $ 555,456
Licensing Agreements | On and after October 20, 2011 |  |  |
Fees Paid and Related Party Transactions [Line Items] |  |  |
Fee percentage | 0.015% |  |

X
- Definition Costs incurred and are directly related to generating license revenue. Licensing arrangements include, but are not limited to, rights to use a patent, copyright, technology, manufacturing process, software or trademark. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.2(e)) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 + Details
Name: | us-gaap_LicenseCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Description of the nature of payments to managing member or general partner for management of the day-to-day business functions of the limited liability company (LLC) or limited partnership (LP), including the fee rate, basis of calculation, relevant accounting period, whether the fee is paid to an entity other than the managing member or general partner, or whether the fee is waived. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 + Details
Name: | us-gaap_ManagementFeeDescription
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Noninterest expense related to directors' fees which are fees paid by an Entity to its directors. Directors' fees may be paid in addition to salary and other benefits. + 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
Name: | us-gaap_NoninterestExpenseDirectorsFees
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of general expenses not normally included in Other Operating Costs and Expenses. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.6) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 + Details
Name: | us-gaap_OtherGeneralExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Base Fee Percentage + References No definition available. + Details
Name: | usl_BaseFeePercentage
Namespace Prefix: | usl_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fees Paid and Related Party Transactions [Line Items] + References No definition available. + Details
Name: | usl_FeesPaidAndRelatedPartyTransactionsLineItems
Namespace Prefix: | usl_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Registration Fees and Other Offering Expenses + References No definition available. + Details
Name: | usl_RegistrationFeesAndOtherOfferingExpenses
Namespace Prefix: | usl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | invest_InvestmentIdentifierSchemeAxis=usl_FundTrustsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_TypeOfArrangementAxis=us-gaap_LicensingAgreementsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentIdentifierSchemeAxis=usl_GroupThreeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |