XML 72 R22.htm IDEA: XBRL DOCUMENT
v2.4.0.8

FEES PAID BY THE FUND AND RELATED PARTY TRANSACTIONS - Additional Information (Detail) (USD $) | 3 Months Ended | 6 Months Ended
--- | --- | ---
Jun. 30, 2013 | Jun. 30, 2012 | Jun. 30, 2013 | Jun. 30, 2012
Fees Paid and Related Party Transactions [Line Items] |  |  |  |
USCF Management Fee |  |  | US12NG is contractually obligated to pay USCF a fee, which is paid monthly, equal to 0.75% per annum of average daily total net assets. |
Percentage of average daily net assets | 0.75% |  | 0.75% |
Licensing fee incurred |  |  | $ 2,949 | $ 2,120
Expense waiver (Note 3) | (18,323) | (12,614) | (32,787) | (28,921)
Licensing Agreements [Member] | First $1,000,000,000 of combined net assets of the funds [Member] |  |  |  |
Fees Paid and Related Party Transactions [Line Items] |  |  |  |
Fee percentage |  |  | 0.04% |
Licensing Agreements [Member] | First $1,000,000,000 of combined net assets of the funds [Member] | Maximum [Member] |  |  |  |
Fees Paid and Related Party Transactions [Line Items] |  |  |  |
Combined assets basis for determining fee percentage | 1,000,000,000 |  | 1,000,000,000 |
Licensing Agreements [Member] | Combined net assets above $1,000,000,000 [Member] |  |  |  |
Fees Paid and Related Party Transactions [Line Items] |  |  |  |
Fee percentage |  |  | 0.02% |
Licensing Agreements [Member] | Combined net assets above $1,000,000,000 [Member] | Minimum [Member] |  |  |  |
Fees Paid and Related Party Transactions [Line Items] |  |  |  |
Combined assets basis for determining fee percentage | 1,000,000,000 |  | 1,000,000,000 |
Licensing Agreements [Member] | On and after October 20, 2011 [Member] |  |  |  |
Fees Paid and Related Party Transactions [Line Items] |  |  |  |
Fee percentage |  |  | 0.015% |
Assets basis for determining fee percentage |  |  | On all net assets |
Future Period - for the year ending December 31, 2013 [Member] |  |  |  |
Fees Paid and Related Party Transactions [Line Items] |  |  |  |
Estimated investor tax reporting cost |  |  | 125,000 |
Future Period - for the year ending December 31, 2013 [Member] | Maximum [Member] |  |  |  |
Fees Paid and Related Party Transactions [Line Items] |  |  |  |
Costs and expenses annual limit for reimbursement |  |  | 0.15% |
US12NG [Member] | Related Public Funds [Member] |  |  |  |
Fees Paid and Related Party Transactions [Line Items] |  |  |  |
Estimated directors' fees and expenses |  |  | $ 560,625 |

X
- Definition Base Amount For Fee Percentage + References No definition available. + Details
Name: | unl_BaseAmountForFeePercentage
Namespace Prefix: | unl_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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

X
- Definition Basis Amount for Fee Percentage + References No definition available. + Details
Name: | unl_BasisAmountForFeePercentage
Namespace Prefix: | unl_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Expense Waiver + References No definition available. + Details
Name: | unl_ExpenseWaiver
Namespace Prefix: | unl_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | unl_FeesPaidAndRelatedPartyTransactionsLineItems
Namespace Prefix: | unl_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of Average Daily Net Assets + References No definition available. + Details
Name: | unl_PercentageOfAverageDailyNetAssets
Namespace Prefix: | unl_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of Change in Costs and Expenses + References No definition available. + Details
Name: | unl_PercentageOfChangeInCostsAndExpenses
Namespace Prefix: | unl_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 6 -Article 5 + Details
Name: | us-gaap_OtherGeneralExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration