v2.4.1.9
Schedule of Investments - Futures Contracts Sold (Detail) (USD $)
Mar. 31, 2015
ProShares Managed Futures Strategy [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) $ 128,417us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Coffee 'C' Futures - ICE, Expires May 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 2us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CoffeeCFuturesIceExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 99,675invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CoffeeCFuturesIceExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 26,006us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CoffeeCFuturesIceExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Copper Futures - COMEX, Expires May 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 4us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CopperFuturesComexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 274,000invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CopperFuturesComexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) (16,262)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CopperFuturesComexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Copper Mini Futures - COMEX, Expires May 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 1us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CopperMiniFuturesComexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 34,250invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CopperMiniFuturesComexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 775us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CopperMiniFuturesComexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Corn Futures - CBT, Expires May 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 10us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CornFuturesCbtExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 188,125invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CornFuturesCbtExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 8,675us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CornFuturesCbtExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Natural Gas Futures - NYMEX, Expires May 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 6us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_NaturalGasFuturesNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 158,400invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_NaturalGasFuturesNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 9,950us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_NaturalGasFuturesNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Natural Gas Mini Futures - NYMEX, Expires May 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 2us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_NaturalGasMiniFuturesNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 13,200invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_NaturalGasMiniFuturesNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 1,200us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_NaturalGasMiniFuturesNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | NY Harbor ULSD Futures-NYMEX, May 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 2us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_NyHarborUlsdFuturesNymexMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 143,472invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_NyHarborUlsdFuturesNymexMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 14,330us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_NyHarborUlsdFuturesNymexMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | RBOB Gasoline Futures - NYMEX, Expires May 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 2us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_RbobGasolineFuturesNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 148,680invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_RbobGasolineFuturesNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 7,543us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_RbobGasolineFuturesNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Silver Mini Futures - ICE, Expires May 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 8us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SilverMiniFuturesIceExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 132,784invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SilverMiniFuturesIceExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 4,544us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SilverMiniFuturesIceExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Sugar #11 Futures - CBT, Expires May 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 13us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SugarElevenFuturesCbtExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 173,701invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SugarElevenFuturesCbtExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 34,600us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SugarElevenFuturesCbtExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Wheat Futures - CBT, Expires May 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 9us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_WheatFuturesCbtExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 230,288invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_WheatFuturesCbtExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 6,700us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_WheatFuturesCbtExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | WTI Crude Oil Futures - NYMEX, Expires May 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 2us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_WtiCrudeOilFuturesNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 95,200invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_WtiCrudeOilFuturesNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 11,260us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_WtiCrudeOilFuturesNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Australian Dollar Fx Currency Futures - CME, Expires June 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 5us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_AustralianDollarFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 379,050invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_AustralianDollarFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 9,500us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_AustralianDollarFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | British Pound Fx Currency Futures - CME, Expires June 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 7us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_BritishPoundFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 649,119invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_BritishPoundFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 15,419us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_BritishPoundFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Canadian Dollar Fx Currency Futures - CME, Expires June 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 5us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CanadianDollarFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 394,600invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CanadianDollarFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 7,000us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CanadianDollarFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Gold Mini Futures - ICE, Expires June 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 6us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_GoldMiniFuturesIceExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 228,239invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_GoldMiniFuturesIceExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 694us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_GoldMiniFuturesIceExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Euro Fx Currency Mini Futures - CME, Expires June 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 8us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_EuroFxCurrencyMiniFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 537,700invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_EuroFxCurrencyMiniFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 15,619us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_EuroFxCurrencyMiniFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Lean Hogs Futures - CME, Expires June 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 8us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_LeanHogsFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 242,560invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_LeanHogsFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 15,910us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_LeanHogsFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Live Cattle Futures - CME, Expires June 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 6us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_LiveCattleFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 365,580invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_LiveCattleFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) (15,290)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_LiveCattleFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Japanese Yen Fx Currency Futures - CME, Expires June 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 4us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_JapaneseYenFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 417,300invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_JapaneseYenFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) 850us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_JapaneseYenFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Swiss Franc Fx Currency Futures - CME, Expires June 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 2us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SwissFrancFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 257,875invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SwissFrancFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) (200)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SwissFrancFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | US Treasury Long Bond Futures - CBT, Expires June 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 6us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_UsTreasuryLongBondFuturesCbtExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 983,250invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_UsTreasuryLongBondFuturesCbtExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) (30,406)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_UsTreasuryLongBondFuturesCbtExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Short VIX Short-Term Futures ETF [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) 6,991,984us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesShortVixShortTermFuturesEtfMember		 [2]
ProShares Short VIX Short-Term Futures ETF [Member] | VIX Futures - CBOE, Expires April 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 7,729us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresAprilTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesShortVixShortTermFuturesEtfMember		 [2]
Notional Amount at Value 125,789,475invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresAprilTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesShortVixShortTermFuturesEtfMember		 [2]
Unrealized Appreciation (Depreciation) 8,591,734us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresAprilTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesShortVixShortTermFuturesEtfMember		 [2]
ProShares Short VIX Short-Term Futures ETF [Member] | VIX Futures - CBOE, Expires May 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 8,675us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesShortVixShortTermFuturesEtfMember		 [2]
Notional Amount at Value 154,631,875invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesShortVixShortTermFuturesEtfMember		 [2]
Unrealized Appreciation (Depreciation) (1,599,750)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesShortVixShortTermFuturesEtfMember		 [2]
ProShares UltraShort Bloomberg Crude Oil [Member]  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) 26,857,473us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortBloombergCrudeOilMember		 [3]
ProShares UltraShort Bloomberg Crude Oil [Member] | Crude Oil - NYMEX, Expires May 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 6,624us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CrudeOilNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortBloombergCrudeOilMember		 [4]
Notional Amount at Value 315,302,400invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CrudeOilNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortBloombergCrudeOilMember		 [4]
Unrealized Appreciation (Depreciation) 17,406,261us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CrudeOilNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortBloombergCrudeOilMember		 [4]
ProShares UltraShort Bloomberg Natural Gas [Member] | Natural Gas-NYMEX, Expires May 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 828us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_NaturalGasNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortBloombergNaturalGasMember		 [5]
Notional Amount at Value 21,859,200invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_NaturalGasNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortBloombergNaturalGasMember		 [5]
Unrealized Appreciation (Depreciation) 859,740us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_NaturalGasNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortBloombergNaturalGasMember		 [5]
ProShares UltraShort Gold [Member]  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) (1,582,081)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [3]
ProShares UltraShort Gold [Member] | Gold Futures-COMEX, Expires June 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 2us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_GoldFuturesComexExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [6]
Notional Amount at Value 236,640invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_GoldFuturesComexExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [6]
Unrealized Appreciation (Depreciation) (6,040)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_GoldFuturesComexExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [6]
ProShares UltraShort Silver [Member]  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) (3,736,183)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [3]
ProShares UltraShort Silver [Member] | Silver Futures-COMEX, Expires May 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 2us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SilverFuturesComexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [7]
Notional Amount at Value 165,980invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SilverFuturesComexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [7]
Unrealized Appreciation (Depreciation) 3,095us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SilverFuturesComexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [7]
ProShares Short Euro [Member] | Euro Fx Currency Futures - CME, Expires June 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 150us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_EuroFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesShortEuroMember		 [8]
Notional Amount at Value 20,163,750invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_EuroFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesShortEuroMember		 [8]
Unrealized Appreciation (Depreciation) 109,769us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_EuroFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesShortEuroMember		 [8]
ProShares UltraShort Australian Dollar [Member] | Australian Dollar Fx Currency Futures - CME, Expires June 2015 [Member] | Futures Contracts Sold [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 530us-gaap_DerivativeNumberOfInstrumentsHeld
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_AustralianDollarFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortAustralianDollarMember		 [9]
Notional Amount at Value 40,179,300invest_DerivativeNotionalAmount
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_AustralianDollarFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortAustralianDollarMember		 [9]
Unrealized Appreciation (Depreciation) $ 419,850us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsSoldMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_AustralianDollarFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortAustralianDollarMember		 [9]
[1] Cash collateral in the amount of $269,253 was pledged to cover margin requirements for open futures contracts as of March 31, 2015.
[2] Cash collateral in the amount of $55,500,260 was pledged to cover margin requirements for open futures contracts as of March 31, 2015.
[3] The positions and counterparties herein are as of March 31, 2015. The Funds continually evaluate different counterparties for their transactions and counterparties are subject to change. New counterparties can be added at anytime.
[4] Cash collateral in the amount of $ 20,594,295 was pledged to cover margin requirements for open futures contracts as of March 31, 2015.
[5] Cash collateral in the amount of $1,708,036 was pledged to cover margin requirements for open futures contracts as of March 31, 2015.
[6] Cash collateral in the amount of $8,800 was pledged to cover margin requirements for open futures contracts as of March 31, 2015.
[7] Cash collateral in the amount of $16,940 was pledged to cover margin requirements for open futures contracts as of March 31, 2015.
[8] Cash collateral in the amount of $511,500 was pledged to cover margin requirements for open futures contracts as of March 31, 2015.
[9] Cash collateral in the amount of $382,125 was pledged to cover margin requirements for open futures contracts as of March 31, 2015.