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

Schedule of Investments (USD $)

Dec. 31, 2014

Dec. 31, 2013

United States [Member] | Money Market Funds [Member]

Unrealized Gain (Loss) on Open Commodity Contracts

$ 9,510,692unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts
/ invest_InvestmentGeographicRegionAxis
= country_US
/ invest_InvestmentSecuritiesClassAxis
= us-gaap_MoneyMarketFundsMember

Market Values

19,522,574us-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

2,009,115us-gaap_InvestmentOwnedBalancePrincipalAmount
/ invest_InvestmentGeographicRegionAxis
= country_US
/ invest_InvestmentSecuritiesClassAxis
= us-gaap_MoneyMarketFundsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_FidelityInstitutionalGovernmentPortfolioClassIMember

Market Values

2,009,115us-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

1unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts
/ invest_InvestmentGeographicRegionAxis
= country_US
/ invest_InvestmentSecuritiesClassAxis
= us-gaap_MoneyMarketFundsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_GoldmanSachsFinancialSquareFundsGovernmentFundClassFsMember

^[1]

Principal Amount

1us-gaap_InvestmentOwnedBalancePrincipalAmount
/ invest_InvestmentGeographicRegionAxis
= country_US
/ invest_InvestmentSecuritiesClassAxis
= us-gaap_MoneyMarketFundsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_GoldmanSachsFinancialSquareFundsGovernmentFundClassFsMember

^[1]

1,002,300us-gaap_InvestmentOwnedBalancePrincipalAmount
/ invest_InvestmentGeographicRegionAxis
= country_US
/ invest_InvestmentSecuritiesClassAxis
= us-gaap_MoneyMarketFundsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_GoldmanSachsFinancialSquareFundsGovernmentFundClassFsMember

Market Values

1,002,300us-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

6,510,691unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts
/ invest_InvestmentGeographicRegionAxis
= country_US
/ invest_InvestmentSecuritiesClassAxis
= us-gaap_MoneyMarketFundsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_MorganStanleyInstitutionalLiquidityFundGovernmentPortfolioMember

Principal Amount

6,510,691us-gaap_InvestmentOwnedBalancePrincipalAmount
/ invest_InvestmentGeographicRegionAxis
= country_US
/ invest_InvestmentSecuritiesClassAxis
= us-gaap_MoneyMarketFundsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_MorganStanleyInstitutionalLiquidityFundGovernmentPortfolioMember

6,510,691us-gaap_InvestmentOwnedBalancePrincipalAmount
/ invest_InvestmentGeographicRegionAxis
= country_US
/ invest_InvestmentSecuritiesClassAxis
= us-gaap_MoneyMarketFundsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_MorganStanleyInstitutionalLiquidityFundGovernmentPortfolioMember

Market Values

6,510,691us-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

3,000,000unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts
/ invest_InvestmentGeographicRegionAxis
= country_US
/ invest_InvestmentSecuritiesClassAxis
= us-gaap_MoneyMarketFundsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_WellsFargoAdvantageGovernmentMoneyMarketFundClassIMember

Principal Amount

3,000,000us-gaap_InvestmentOwnedBalancePrincipalAmount
/ invest_InvestmentGeographicRegionAxis
= country_US
/ invest_InvestmentSecuritiesClassAxis
= us-gaap_MoneyMarketFundsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_WellsFargoAdvantageGovernmentMoneyMarketFundClassIMember

10,000,468us-gaap_InvestmentOwnedBalancePrincipalAmount
/ invest_InvestmentGeographicRegionAxis
= country_US
/ invest_InvestmentSecuritiesClassAxis
= us-gaap_MoneyMarketFundsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_WellsFargoAdvantageGovernmentMoneyMarketFundClassIMember

Market Values

10,000,468us-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

3,000,000us-gaap_InvestmentOwnedBalancePrincipalAmount
/ invest_InvestmentAxis
= us-gaap_CashEquivalentsMember
/ invest_InvestmentSecuritiesClassAxis
= us-gaap_USTreasurySecuritiesMember
/ invest_InvestmentSecuritiesSeriesAxis
= us-gaap_USTreasuryBillSecuritiesMember

Market Values

2,999,455us-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

3,000,000us-gaap_InvestmentOwnedBalancePrincipalAmount
/ invest_InvestmentAxis
= us-gaap_CashEquivalentsMember
/ invest_InvestmentSecuritiesClassAxis
= us-gaap_USTreasurySecuritiesMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_UsTreasuryBillSecuritiesOneMember

Market Values

2,999,504us-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

12,510,147unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts
/ invest_InvestmentAxis
= us-gaap_CashEquivalentsMember
/ invest_InvestmentGeographicRegionAxis
= country_US

Market Values

22,522,078us-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

537us-gaap_InvestmentOwnedBalanceContracts
/ invest_InvestmentGeographicRegionAxis
= unl_UnitedStatesContractsMember
/ us-gaap_InvestmentTypeAxis
= unl_OpenFuturesContractsLongMember

^[2]

656us-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]

1,090,050unl_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

44us-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

45us-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

45us-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

45us-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

45us-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

44us-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

45us-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

45us-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

45us-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

45us-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

44us-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

45us-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

54us-gaap_InvestmentOwnedBalanceContracts
/ invest_InvestmentGeographicRegionAxis
= unl_UnitedStatesContractsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_NymexNaturalGasFuturesNgFebruary2014ContractsExpiringJanuary2014Member
/ us-gaap_InvestmentTypeAxis
= unl_OpenFuturesContractsLongMember

Unrealized Gain (Loss) on Open Commodity Contracts

91,970unl_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

55us-gaap_InvestmentOwnedBalanceContracts
/ invest_InvestmentGeographicRegionAxis
= unl_UnitedStatesContractsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_NymexNaturalGasFuturesNgMarch2014ContractsExpiringFebruary2014Member
/ us-gaap_InvestmentTypeAxis
= unl_OpenFuturesContractsLongMember

Unrealized Gain (Loss) on Open Commodity Contracts

143,450unl_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

54us-gaap_InvestmentOwnedBalanceContracts
/ invest_InvestmentGeographicRegionAxis
= unl_UnitedStatesContractsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_NymexNaturalGasFuturesNgApril2014ContractsExpiringMarch2014Member
/ us-gaap_InvestmentTypeAxis
= unl_OpenFuturesContractsLongMember

Unrealized Gain (Loss) on Open Commodity Contracts

69,830unl_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

55us-gaap_InvestmentOwnedBalanceContracts
/ invest_InvestmentGeographicRegionAxis
= unl_UnitedStatesContractsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_NymexNaturalGasFuturesNgMay2014ContractsExpiringApril2014Member
/ us-gaap_InvestmentTypeAxis
= unl_OpenFuturesContractsLongMember

Unrealized Gain (Loss) on Open Commodity Contracts

34,850unl_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

54us-gaap_InvestmentOwnedBalanceContracts
/ invest_InvestmentGeographicRegionAxis
= unl_UnitedStatesContractsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_NymexNaturalGasFuturesNgJune2014ContractsExpiringMay2014Member
/ us-gaap_InvestmentTypeAxis
= unl_OpenFuturesContractsLongMember

Unrealized Gain (Loss) on Open Commodity Contracts

19,540unl_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

55us-gaap_InvestmentOwnedBalanceContracts
/ invest_InvestmentGeographicRegionAxis
= unl_UnitedStatesContractsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_NymexNaturalGasFuturesNgJuly2014ContractsExpiringJune2014Member
/ us-gaap_InvestmentTypeAxis
= unl_OpenFuturesContractsLongMember

Unrealized Gain (Loss) on Open Commodity Contracts

84,390unl_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

55us-gaap_InvestmentOwnedBalanceContracts
/ invest_InvestmentGeographicRegionAxis
= unl_UnitedStatesContractsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_NymexNaturalGasFuturesNgAugust2014ContractsExpiringJuly2014Member
/ us-gaap_InvestmentTypeAxis
= unl_OpenFuturesContractsLongMember

Unrealized Gain (Loss) on Open Commodity Contracts

101,750unl_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

55us-gaap_InvestmentOwnedBalanceContracts
/ invest_InvestmentGeographicRegionAxis
= unl_UnitedStatesContractsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_NymexNaturalGasFuturesNgSeptember2014ContractsExpiringAugust2014Member
/ us-gaap_InvestmentTypeAxis
= unl_OpenFuturesContractsLongMember

Unrealized Gain (Loss) on Open Commodity Contracts

198,780unl_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

54us-gaap_InvestmentOwnedBalanceContracts
/ invest_InvestmentGeographicRegionAxis
= unl_UnitedStatesContractsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_NymexNaturalGasFuturesNgOctober2014ContractsExpiringSeptember2014Member
/ us-gaap_InvestmentTypeAxis
= unl_OpenFuturesContractsLongMember

Unrealized Gain (Loss) on Open Commodity Contracts

120,580unl_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

55us-gaap_InvestmentOwnedBalanceContracts
/ invest_InvestmentGeographicRegionAxis
= unl_UnitedStatesContractsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_NymexNaturalGasFuturesNgNovember2014ContractsExpiringOctober2014Member
/ us-gaap_InvestmentTypeAxis
= unl_OpenFuturesContractsLongMember

Unrealized Gain (Loss) on Open Commodity Contracts

55,320unl_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

55us-gaap_InvestmentOwnedBalanceContracts
/ invest_InvestmentGeographicRegionAxis
= unl_UnitedStatesContractsMember
/ invest_InvestmentSecuritiesSeriesAxis
= unl_NymexNaturalGasFuturesNgDecember2014ContractsExpiringNovember2014Member
/ us-gaap_InvestmentTypeAxis
= unl_OpenFuturesContractsLongMember

Unrealized Gain (Loss) on Open Commodity Contracts

194,730unl_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

55us-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.

X

- Definition

Percentage of Partners Capital

+ References

No definition available.

+ Details

Name:	unl_PercentageOfPartnersCapital
Namespace Prefix:	unl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Unrealized gain (loss) on open commodity futures and cleared swap contracts.

+ References

No definition available.

+ Details

Name:	unl_UnrealizedGainLossOnOpenCommodityFuturesAndClearedSwapContracts
Namespace Prefix:	unl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Balance held at close of period in number of contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 4

-Subparagraph (SX 210.12-12C.Column B)

-URI http://asc.fasb.org/extlink&oid=34726532&loc=d3e611225-123010



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 6

-Subparagraph (SX 210.12-14.Column B)

-URI http://asc.fasb.org/extlink&oid=34726532&loc=d3e611322-123010



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-12.Column B)

-URI http://asc.fasb.org/extlink&oid=34726532&loc=d3e611133-123010



Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 12C

-Paragraph Column B

-Article 12



Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 12

-Paragraph Column B

-Article 12



Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 14

-Paragraph Column B

-Article 12

+ Details

Name:	us-gaap_InvestmentOwnedBalanceContracts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

X

- Definition

For investments which are quantified by principal amount, the principle balance held at close of period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 4

-Subparagraph (SX 210.12-12C.Column B)

-URI http://asc.fasb.org/extlink&oid=34726532&loc=d3e611225-123010



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 6

-Subparagraph (SX 210.12-14.Column B)

-URI http://asc.fasb.org/extlink&oid=34726532&loc=d3e611322-123010



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 1

-Subparagraph (SX 210.12-12.Column B)

-URI http://asc.fasb.org/extlink&oid=34726532&loc=d3e611133-123010



Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 12C

-Paragraph Column B

-Article 12



Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 12

-Paragraph Column B

-Article 12



Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 14

-Paragraph Column B

-Article 12

+ Details

Name:	us-gaap_InvestmentOwnedBalancePrincipalAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Nominal or face amount on the investment owned.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Underlying

-URI http://asc.fasb.org/extlink&oid=6527499



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 10

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6431724&loc=d3e32938-113948



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 20

-Section 10

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6438156&loc=d3e57880-113973

+ Details

Name:	us-gaap_InvestmentOwnedUnderlyingFaceAmountAtMarketValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	invest_InvestmentAxis=us-gaap_CashEquivalentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	invest_InvestmentGeographicRegionAxis=country_US
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=unl_OpenFuturesContractsLongMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: