XML 36 R3.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Schedule of Investments (USD $) | Dec. 31, 2014 | Dec. 31, 2013
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United States [Member] | Money Market Funds [Member] |  |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | $ 9,510,692 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember |  |  |
Market Values |  |  | 19,522,574 us-gaap_InvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember |
% of Partners' Capital | 57.90%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember |  | 71.04%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember |
United States [Member] | Fidelity Institutional Government Portfolio - Class I [Member] | Money Market Funds [Member] |  |  |  |
Principal Amount |  |  | 2,009,115 us-gaap_InvestmentOwnedBalancePrincipalAmount / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_FidelityInstitutionalGovernmentPortfolioClassIMember |
Market Values |  |  | 2,009,115 us-gaap_InvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_FidelityInstitutionalGovernmentPortfolioClassIMember |
% of Partners' Capital |  |  | 7.31%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_FidelityInstitutionalGovernmentPortfolioClassIMember |
United States [Member] | Goldman Sachs Financial Square Funds - Government Fund - Class FS [Member] | Money Market Funds [Member] |  |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | 1 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_GoldmanSachsFinancialSquareFundsGovernmentFundClassFsMember | [1] |  |
Principal Amount | 1 us-gaap_InvestmentOwnedBalancePrincipalAmount / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_GoldmanSachsFinancialSquareFundsGovernmentFundClassFsMember | [1] | 1,002,300 us-gaap_InvestmentOwnedBalancePrincipalAmount / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_GoldmanSachsFinancialSquareFundsGovernmentFundClassFsMember |
Market Values |  |  | 1,002,300 us-gaap_InvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_GoldmanSachsFinancialSquareFundsGovernmentFundClassFsMember |
% of Partners' Capital | 0.00%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_GoldmanSachsFinancialSquareFundsGovernmentFundClassFsMember | [1] | 3.65%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_GoldmanSachsFinancialSquareFundsGovernmentFundClassFsMember |
United States [Member] | Morgan Stanley Institutional Liquidity Fund - Government Portfolio [Member] | Money Market Funds [Member] |  |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | 6,510,691 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_MorganStanleyInstitutionalLiquidityFundGovernmentPortfolioMember |  |  |
Principal Amount | 6,510,691 us-gaap_InvestmentOwnedBalancePrincipalAmount / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_MorganStanleyInstitutionalLiquidityFundGovernmentPortfolioMember |  | 6,510,691 us-gaap_InvestmentOwnedBalancePrincipalAmount / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_MorganStanleyInstitutionalLiquidityFundGovernmentPortfolioMember |
Market Values |  |  | 6,510,691 us-gaap_InvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_MorganStanleyInstitutionalLiquidityFundGovernmentPortfolioMember |
% of Partners' Capital | 39.64%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_MorganStanleyInstitutionalLiquidityFundGovernmentPortfolioMember |  | 23.69%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_MorganStanleyInstitutionalLiquidityFundGovernmentPortfolioMember |
United States [Member] | Wells Fargo Advantage Government Money Market Fund - Class I [Member] | Money Market Funds [Member] |  |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | 3,000,000 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_WellsFargoAdvantageGovernmentMoneyMarketFundClassIMember |  |  |
Principal Amount | 3,000,000 us-gaap_InvestmentOwnedBalancePrincipalAmount / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_WellsFargoAdvantageGovernmentMoneyMarketFundClassIMember |  | 10,000,468 us-gaap_InvestmentOwnedBalancePrincipalAmount / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_WellsFargoAdvantageGovernmentMoneyMarketFundClassIMember |
Market Values |  |  | 10,000,468 us-gaap_InvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_WellsFargoAdvantageGovernmentMoneyMarketFundClassIMember |
% of Partners' Capital | 18.26%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_WellsFargoAdvantageGovernmentMoneyMarketFundClassIMember |  | 36.39%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = country_US / invest_InvestmentSecuritiesClassAxis = us-gaap_MoneyMarketFundsMember / invest_InvestmentSecuritiesSeriesAxis = unl_WellsFargoAdvantageGovernmentMoneyMarketFundClassIMember |
Cash Equivalents [Member] | U.S. Treasury Bill, 0.06%, 4/30/15 [Member] | US Treasury Securities [Member] |  |  |  |
Principal Amount | 3,000,000 us-gaap_InvestmentOwnedBalancePrincipalAmount / invest_InvestmentAxis = us-gaap_CashEquivalentsMember / invest_InvestmentSecuritiesClassAxis = us-gaap_USTreasurySecuritiesMember / invest_InvestmentSecuritiesSeriesAxis = us-gaap_USTreasuryBillSecuritiesMember |  |  |
Market Values | 2,999,455 us-gaap_InvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = us-gaap_CashEquivalentsMember / invest_InvestmentSecuritiesClassAxis = us-gaap_USTreasurySecuritiesMember / invest_InvestmentSecuritiesSeriesAxis = us-gaap_USTreasuryBillSecuritiesMember |  |  |
% of Partners' Capital | 18.26%unl_PercentageOfPartnersCapital / invest_InvestmentAxis = us-gaap_CashEquivalentsMember / invest_InvestmentSecuritiesClassAxis = us-gaap_USTreasurySecuritiesMember / invest_InvestmentSecuritiesSeriesAxis = us-gaap_USTreasuryBillSecuritiesMember |  |  |
Cash Equivalents [Member] | U.S. Treasury Bill, 0.07%, 3/27/2014 [Member] | US Treasury Securities [Member] |  |  |  |
Principal Amount |  |  | 3,000,000 us-gaap_InvestmentOwnedBalancePrincipalAmount / invest_InvestmentAxis = us-gaap_CashEquivalentsMember / invest_InvestmentSecuritiesClassAxis = us-gaap_USTreasurySecuritiesMember / invest_InvestmentSecuritiesSeriesAxis = unl_UsTreasuryBillSecuritiesOneMember |
Market Values |  |  | 2,999,504 us-gaap_InvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = us-gaap_CashEquivalentsMember / invest_InvestmentSecuritiesClassAxis = us-gaap_USTreasurySecuritiesMember / invest_InvestmentSecuritiesSeriesAxis = unl_UsTreasuryBillSecuritiesOneMember |
% of Partners' Capital |  |  | 10.91%unl_PercentageOfPartnersCapital / invest_InvestmentAxis = us-gaap_CashEquivalentsMember / invest_InvestmentSecuritiesClassAxis = us-gaap_USTreasurySecuritiesMember / invest_InvestmentSecuritiesSeriesAxis = unl_UsTreasuryBillSecuritiesOneMember |
Cash Equivalents [Member] | United States [Member] |  |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | 12,510,147 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentAxis = us-gaap_CashEquivalentsMember / invest_InvestmentGeographicRegionAxis = country_US |  |  |
Market Values |  |  | 22,522,078 us-gaap_InvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = us-gaap_CashEquivalentsMember / invest_InvestmentGeographicRegionAxis = country_US |
% of Partners' Capital | 76.16%unl_PercentageOfPartnersCapital / invest_InvestmentAxis = us-gaap_CashEquivalentsMember / invest_InvestmentGeographicRegionAxis = country_US |  | 81.95%unl_PercentageOfPartnersCapital / invest_InvestmentAxis = us-gaap_CashEquivalentsMember / invest_InvestmentGeographicRegionAxis = country_US |
Open Futures Contracts, Long [Member] | United States Contracts [Member] |  |  |  |
Number of Contracts | 537 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember | [2] | 656 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember | [3]
Unrealized Gain (Loss) on Open Commodity Contracts | (4,919,890)unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember | [2] | 1,090,050 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember | [3]
% of Partners' Capital | (29.95%)unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember | [2] | 3.97%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember | [3]
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG February 2015 contracts, expiring January 2015 [Member] |  |  |  |
Number of Contracts | 44 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgTenMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | (575,580)unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgTenMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
% of Partners' Capital | (3.50%)unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgTenMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG March 2015 contracts, expiring February 2015 [Member] |  |  |  |
Number of Contracts | 45 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgElevenMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | (682,500)unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgElevenMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
% of Partners' Capital | (4.15%)unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgElevenMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG April 2015 contracts, expiring March 2015 (Member) |  |  |  |
Number of Contracts | 45 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgTwelveMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | (469,990)unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgTwelveMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
% of Partners' Capital | (2.86%)unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgTwelveMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG May 2015 contracts, expiring April 2015 [Member] |  |  |  |
Number of Contracts | 45 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgOneMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | (487,830)unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgOneMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
% of Partners' Capital | (2.97%)unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgOneMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG June 2015 contracts, expiring May 2015 [Member] |  |  |  |
Number of Contracts | 45 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgTwoMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | (431,920)unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgTwoMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
% of Partners' Capital | (2.63%)unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgTwoMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG July 2015 contracts, expiring June 2015 [Member] |  |  |  |
Number of Contracts | 44 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgThreeMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | (470,800)unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgThreeMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
% of Partners' Capital | (2.87%)unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgThreeMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG August 2015 contracts, expiring July 2015 [Member] |  |  |  |
Number of Contracts | 45 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgFourMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | (383,790)unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgFourMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
% of Partners' Capital | (2.34%)unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgFourMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG September 2015 contracts, expiring August 2015 [Member] |  |  |  |
Number of Contracts | 45 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgFiveMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | (340,100)unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgFiveMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
% of Partners' Capital | (2.07%)unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgFiveMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG October 2015 contracts, expiring September 2015 [Member] |  |  |  |
Number of Contracts | 45 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgSixMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | (336,770)unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgSixMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
% of Partners' Capital | (2.05%)unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgSixMember / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG November 2015 contracts, expiring October 2015 [Member] |  |  |  |
Number of Contracts | 45 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgNovember2015ContractsExpiringOctober2015Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | (284,380)unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgNovember2015ContractsExpiringOctober2015Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
% of Partners' Capital | (1.73%)unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgNovember2015ContractsExpiringOctober2015Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG December 2015 contracts, expiring November 2015 [Member] |  |  |  |
Number of Contracts | 44 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgDecember2015ContractsExpiringNovember2015Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | (277,720)unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgDecember2015ContractsExpiringNovember2015Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
% of Partners' Capital | (1.69%)unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgDecember2015ContractsExpiringNovember2015Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG January 2016 contracts, expiring December 2015 [Member] |  |  |  |
Number of Contracts | 45 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgJanuary2016ContractsExpiringDecember2015Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Unrealized Gain (Loss) on Open Commodity Contracts | (178,510)unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgJanuary2016ContractsExpiringDecember2015Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
% of Partners' Capital | (1.09%)unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgJanuary2016ContractsExpiringDecember2015Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |  |  |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG February 2014 contracts, expiring January 2014 [Member] |  |  |  |
Number of Contracts |  |  | 54 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgFebruary2014ContractsExpiringJanuary2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Unrealized Gain (Loss) on Open Commodity Contracts |  |  | 91,970 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgFebruary2014ContractsExpiringJanuary2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
% of Partners' Capital |  |  | 0.34%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgFebruary2014ContractsExpiringJanuary2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG March 2014 contracts, expiring February 2014 [Member] |  |  |  |
Number of Contracts |  |  | 55 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgMarch2014ContractsExpiringFebruary2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Unrealized Gain (Loss) on Open Commodity Contracts |  |  | 143,450 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgMarch2014ContractsExpiringFebruary2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
% of Partners' Capital |  |  | 0.52%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgMarch2014ContractsExpiringFebruary2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG April 2014 contracts, expiring March 2014 [Member] |  |  |  |
Number of Contracts |  |  | 54 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgApril2014ContractsExpiringMarch2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Unrealized Gain (Loss) on Open Commodity Contracts |  |  | 69,830 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgApril2014ContractsExpiringMarch2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
% of Partners' Capital |  |  | 0.25%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgApril2014ContractsExpiringMarch2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG May 2014 contracts, expiring April 2014 [Member] |  |  |  |
Number of Contracts |  |  | 55 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgMay2014ContractsExpiringApril2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Unrealized Gain (Loss) on Open Commodity Contracts |  |  | 34,850 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgMay2014ContractsExpiringApril2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
% of Partners' Capital |  |  | 0.13%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgMay2014ContractsExpiringApril2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG June 2014 contracts, expiring May 2014 [Member] |  |  |  |
Number of Contracts |  |  | 54 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgJune2014ContractsExpiringMay2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Unrealized Gain (Loss) on Open Commodity Contracts |  |  | 19,540 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgJune2014ContractsExpiringMay2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
% of Partners' Capital |  |  | 0.07%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgJune2014ContractsExpiringMay2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG July 2014 contracts, expiring June 2014 [Member] |  |  |  |
Number of Contracts |  |  | 55 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgJuly2014ContractsExpiringJune2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Unrealized Gain (Loss) on Open Commodity Contracts |  |  | 84,390 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgJuly2014ContractsExpiringJune2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
% of Partners' Capital |  |  | 0.31%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgJuly2014ContractsExpiringJune2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG August 2014 contracts, expiring July 2014 [Member] |  |  |  |
Number of Contracts |  |  | 55 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgAugust2014ContractsExpiringJuly2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Unrealized Gain (Loss) on Open Commodity Contracts |  |  | 101,750 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgAugust2014ContractsExpiringJuly2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
% of Partners' Capital |  |  | 0.37%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgAugust2014ContractsExpiringJuly2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG September 2014 contracts, expiring August 2014 [Member] |  |  |  |
Number of Contracts |  |  | 55 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgSeptember2014ContractsExpiringAugust2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Unrealized Gain (Loss) on Open Commodity Contracts |  |  | 198,780 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgSeptember2014ContractsExpiringAugust2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
% of Partners' Capital |  |  | 0.72%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgSeptember2014ContractsExpiringAugust2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG October 2014 contracts, expiring September 2014 [Member] |  |  |  |
Number of Contracts |  |  | 54 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgOctober2014ContractsExpiringSeptember2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Unrealized Gain (Loss) on Open Commodity Contracts |  |  | 120,580 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgOctober2014ContractsExpiringSeptember2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
% of Partners' Capital |  |  | 0.44%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgOctober2014ContractsExpiringSeptember2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG November 2014 contracts, expiring October 2014 [Member] |  |  |  |
Number of Contracts |  |  | 55 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgNovember2014ContractsExpiringOctober2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Unrealized Gain (Loss) on Open Commodity Contracts |  |  | 55,320 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgNovember2014ContractsExpiringOctober2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
% of Partners' Capital |  |  | 0.20%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgNovember2014ContractsExpiringOctober2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG December 2014 contracts, expiring November 2014 [Member] |  |  |  |
Number of Contracts |  |  | 55 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgDecember2014ContractsExpiringNovember2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Unrealized Gain (Loss) on Open Commodity Contracts |  |  | 194,730 unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgDecember2014ContractsExpiringNovember2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
% of Partners' Capital |  |  | 0.71%unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgDecember2014ContractsExpiringNovember2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Open Futures Contracts, Long [Member] | United States Contracts [Member] | NYMEX Natural Gas Futures NG January 2015 contracts, expiring December 2014 [Member] |  |  |  |
Number of Contracts |  |  | 55 us-gaap_InvestmentOwnedBalanceContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgJanuary2015ContractsExpiringDecember2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
Unrealized Gain (Loss) on Open Commodity Contracts |  |  | $ (25,140)unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgJanuary2015ContractsExpiringDecember2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
% of Partners' Capital |  |  | (0.09%)unl_PercentageOfPartnersCapital / invest_InvestmentGeographicRegionAxis = unl_UnitedStatesContractsMember / invest_InvestmentSecuritiesSeriesAxis = unl_NymexNaturalGasFuturesNgJanuary2015ContractsExpiringDecember2014Member / us-gaap_InvestmentTypeAxis = unl_OpenFuturesContractsLongMember |
[1] | Represents less than 0.005%.
[2] | Collateral amounted to $5,525,172 on open futures contracts.
[3] | Collateral amounted to $949,087 on open futures contracts.

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