XML 47 R5.htm IDEA: XBRL DOCUMENT v2.4.1.9
Condensed Schedule of Investments (USD $)
Dec. 31, 2014
Dec. 31, 2013
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts $ 5,792,535us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet $ 6,652,432us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
Unrealized Currency Loss (669,947)dwsf_InvestmentOwnedUnrealizedCurrencyGainLoss (689,577)dwsf_InvestmentOwnedUnrealizedCurrencyGainLoss
Unrealized Currency Loss Percentage of Partners' Capital (in hundredths) (0.57%)dwsf_UnrealizedCurrencyGainPercentageOfPartnersCapital (0.47%)dwsf_UnrealizedCurrencyGainPercentageOfPartnersCapital
Net fair value 5,792,535us-gaap_InvestmentOwnedAtFairValue 6,652,432us-gaap_InvestmentOwnedAtFairValue
Fair value Percentage of Partners' Capital (in hundredths) 4.91%dwsf_FairValuePercentageOfPartnersCapital 4.54%dwsf_FairValuePercentageOfPartnersCapital
Contracts Purchased [Member] | Futures And Forward Contracts [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts 1,307,965us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 3,023,628us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Percentage of Partners' Capital (in hundredths) 1.11%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 2.07%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Contracts Purchased [Member] | Futures And Forward Contracts [Member] | Commodity [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts (1,909,532)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 (1,214,349)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Percentage of Partners' Capital (in hundredths) (1.62%)us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 (0.82%)us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Contracts Purchased [Member] | Futures And Forward Contracts [Member] | Equity [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts 236,709us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_EquityContractMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 3,462,235us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_EquityContractMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Percentage of Partners' Capital (in hundredths) 0.20%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_EquityContractMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 2.36%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_EquityContractMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Contracts Purchased [Member] | Futures And Forward Contracts [Member] | Foreign Currency [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts 52,035us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 1,349,914us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Percentage of Partners' Capital (in hundredths) 0.04%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 0.92%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Contracts Purchased [Member] | Futures And Forward Contracts [Member] | Interest Rate [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts 2,928,753us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 (574,172)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Percentage of Partners' Capital (in hundredths) 2.48%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 (0.39%)us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Contracts Sold [Member] | Futures And Forward Contracts [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts 5,154,517us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 4,318,381us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Percentage of Partners' Capital (in hundredths) 4.37%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 2.94%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Contracts Sold [Member] | Futures And Forward Contracts [Member] | Commodity [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts 4,259,593us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 2,107,872us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Percentage of Partners' Capital (in hundredths) 3.61%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 1.44%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Contracts Sold [Member] | Futures And Forward Contracts [Member] | Equity [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts (97,922)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_EquityContractMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 32,409us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_EquityContractMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Percentage of Partners' Capital (in hundredths) (0.08%)us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_EquityContractMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 0.02%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_EquityContractMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Contracts Sold [Member] | Futures And Forward Contracts [Member] | Foreign Currency [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts 991,501us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 927,755us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Percentage of Partners' Capital (in hundredths) 0.84%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 0.63%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Contracts Sold [Member] | Futures And Forward Contracts [Member] | Interest Rate [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts 1,345us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 1,250,345us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Percentage of Partners' Capital (in hundredths) 0.00%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 [1] 0.85%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Morgan Stanley Smith Barney Spectrum Technical L.P. [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts 604,870us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember		 1,225,590us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
Unrealized Currency Loss (3,465,597)dwsf_InvestmentOwnedUnrealizedCurrencyGainLoss
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember		 (3,447,831)dwsf_InvestmentOwnedUnrealizedCurrencyGainLoss
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
Unrealized Currency Loss Percentage of Partners' Capital (in hundredths) (3.17%)dwsf_UnrealizedCurrencyGainPercentageOfPartnersCapital
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember		 (2.56%)dwsf_UnrealizedCurrencyGainPercentageOfPartnersCapital
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
Net fair value 604,870us-gaap_InvestmentOwnedAtFairValue
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember		 1,225,590us-gaap_InvestmentOwnedAtFairValue
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
Fair value Percentage of Partners' Capital (in hundredths) 0.55%dwsf_FairValuePercentageOfPartnersCapital
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember		 0.91%dwsf_FairValuePercentageOfPartnersCapital
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
Morgan Stanley Smith Barney Spectrum Technical L.P. [Member] | Contracts Purchased [Member] | Futures And Forward Contracts [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts 839,282us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 2,805,307us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Percentage of Partners' Capital (in hundredths) 0.77%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 2.08%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Morgan Stanley Smith Barney Spectrum Technical L.P. [Member] | Contracts Purchased [Member] | Futures And Forward Contracts [Member] | Commodity [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts (605,582)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 (204,694)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Percentage of Partners' Capital (in hundredths) (0.55%)us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 (0.15%)us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Morgan Stanley Smith Barney Spectrum Technical L.P. [Member] | Contracts Purchased [Member] | Futures And Forward Contracts [Member] | Equity [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts 539,849us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_EquityContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 3,109,753us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_EquityContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Percentage of Partners' Capital (in hundredths) 0.49%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_EquityContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 2.31%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_EquityContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Morgan Stanley Smith Barney Spectrum Technical L.P. [Member] | Contracts Purchased [Member] | Futures And Forward Contracts [Member] | Foreign Currency [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts (775,708)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 300,680us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Percentage of Partners' Capital (in hundredths) (0.71%)us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 0.22%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Morgan Stanley Smith Barney Spectrum Technical L.P. [Member] | Contracts Purchased [Member] | Futures And Forward Contracts [Member] | Interest Rate [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts 1,680,723us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 (400,432)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Percentage of Partners' Capital (in hundredths) 1.54%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember		 (0.30%)us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_LongMember
Morgan Stanley Smith Barney Spectrum Technical L.P. [Member] | Contracts Sold [Member] | Futures And Forward Contracts [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts 3,231,185us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 1,868,114us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Percentage of Partners' Capital (in hundredths) 2.95%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 1.39%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Morgan Stanley Smith Barney Spectrum Technical L.P. [Member] | Contracts Sold [Member] | Futures And Forward Contracts [Member] | Commodity [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts 1,735,517us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 768,610us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Percentage of Partners' Capital (in hundredths) 1.58%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 0.57%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_CommodityContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Morgan Stanley Smith Barney Spectrum Technical L.P. [Member] | Contracts Sold [Member] | Futures And Forward Contracts [Member] | Equity [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts (58,649)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_EquityContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 22,944us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_EquityContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Percentage of Partners' Capital (in hundredths) (0.05%)us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_EquityContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 0.02%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_EquityContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Morgan Stanley Smith Barney Spectrum Technical L.P. [Member] | Contracts Sold [Member] | Futures And Forward Contracts [Member] | Foreign Currency [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts 1,565,204us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 497,611us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Percentage of Partners' Capital (in hundredths) 1.43%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 0.37%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_ForeignExchangeContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Morgan Stanley Smith Barney Spectrum Technical L.P. [Member] | Contracts Sold [Member] | Futures And Forward Contracts [Member] | Interest Rate [Member]    
Investment Holdings [Line Items]    
Net unrealized gain/(loss) on open contracts $ (10,887)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 $ 578,949us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
Percentage of Partners' Capital (in hundredths) (0.01%)us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember		 0.43%us-gaap_InvestmentOwnedPercentOfNetAssets
/ us-gaap_DerivativeByNatureAxis
= dwsf_FuturesAndForwardContractsMember
/ us-gaap_DerivativeInstrumentRiskAxis
= us-gaap_InterestRateContractMember
/ dei_LegalEntityAxis
= dwsf_MorganStanleySmithBarneySpectrumTechnicalLPMember
/ us-gaap_PositionAxis
= us-gaap_ShortMember
[1] Amount less than 0.005%.