v2.4.1.9
Schedule of Investments - Futures Contracts Purchased (Detail) (USD $)
 3 Months Ended
Mar. 31, 2015
Contract
ProShares Managed Futures Strategy [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) $ (45,184)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Cocoa Futures - ICE, Expires May 2015 [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 16ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CocoaFuturesIceExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 431,840ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CocoaFuturesIceExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) (39,713)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CocoaFuturesIceExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Cotton No. 2 Futures - ICE, Expires May 2015 [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 8ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CottonNoTwoFuturesIceExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 252,400ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CottonNoTwoFuturesIceExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) (633)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CottonNoTwoFuturesIceExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | Soybean Futures - CBT, Expires May 2015 [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 5ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SoybeanFuturesCbtExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 243,313ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SoybeanFuturesCbtExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) (3,244)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SoybeanFuturesCbtExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares Managed Futures Strategy [Member] | US 10 YR Note Futures - CBT, Expires June 2015 [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 10ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_UsTenYrNoteFuturesCbtExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Notional Amount at Value 1,289,063ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_UsTenYrNoteFuturesCbtExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
Unrealized Appreciation (Depreciation) (1,594)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_UsTenYrNoteFuturesCbtExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesManagedFuturesStrategyMember		 [1]
ProShares VIX Short-Term Futures ETF [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) (5,106,111)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixShortTermFuturesEtfMember		 [2]
ProShares VIX Short-Term Futures ETF [Member] | VIX Futures - CBOE, Expires April 2015 [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 4,166ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresAprilTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixShortTermFuturesEtfMember		 [2]
Notional Amount at Value 67,801,650ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresAprilTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixShortTermFuturesEtfMember		 [2]
Unrealized Appreciation (Depreciation) (5,816,262)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresAprilTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixShortTermFuturesEtfMember		 [2]
ProShares VIX Short-Term Futures ETF [Member] | VIX Futures - CBOE, Expires May 2015 [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 4,594ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixShortTermFuturesEtfMember		 [2]
Notional Amount at Value 81,888,050ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixShortTermFuturesEtfMember		 [2]
Unrealized Appreciation (Depreciation) 710,151us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixShortTermFuturesEtfMember		 [2]
ProShares VIX Mid-Term Futures ETF [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) (500,390)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixMidTermFuturesEtfMember		 [3]
ProShares VIX Mid-Term Futures ETF [Member] | VIX Futures - CBOE, Expires July 2015 [Member ] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 235ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresJulyTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixMidTermFuturesEtfMember		 [3]
Notional Amount at Value 4,388,625ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresJulyTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixMidTermFuturesEtfMember		 [3]
Unrealized Appreciation (Depreciation) (167,050)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresJulyTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixMidTermFuturesEtfMember		 [3]
ProShares VIX Mid-Term Futures ETF [Member] | VIX Futures - CBOE, Expires August 2015 [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 497ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresAugustTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixMidTermFuturesEtfMember		 [3]
Notional Amount at Value 9,380,875ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresAugustTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixMidTermFuturesEtfMember		 [3]
Unrealized Appreciation (Depreciation) (449,540)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresAugustTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixMidTermFuturesEtfMember		 [3]
ProShares VIX Mid-Term Futures ETF [Member] | VIX Futures - CBOE, Expires September 2015 [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 497ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresSeptemberTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixMidTermFuturesEtfMember		 [3]
Notional Amount at Value 9,529,975ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresSeptemberTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixMidTermFuturesEtfMember		 [3]
Unrealized Appreciation (Depreciation) 57,125us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresSeptemberTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixMidTermFuturesEtfMember		 [3]
ProShares VIX Mid-Term Futures ETF [Member] | VIX Futures - CBOE, Expires October 2015 [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 261ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresOctoberTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixMidTermFuturesEtfMember		 [3]
Notional Amount at Value 5,082,975ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresOctoberTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixMidTermFuturesEtfMember		 [3]
Unrealized Appreciation (Depreciation) 59,075us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresOctoberTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesVixMidTermFuturesEtfMember		 [3]
ProShares Ultra VIX Short-Term Futures ETF [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) (48,925,693)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember		 [4]
ProShares Ultra VIX Short-Term Futures ETF [Member] | VIX Futures - CBOE, Expires April 2015 [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 38,547ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresAprilTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember		 [4]
Notional Amount at Value 627,352,425ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresAprilTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember		 [4]
Unrealized Appreciation (Depreciation) (55,127,903)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresAprilTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember		 [4]
ProShares Ultra VIX Short-Term Futures ETF [Member] | VIX Futures - CBOE, Expires May 2015 [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 42,693ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember		 [4]
Notional Amount at Value 761,002,725ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember		 [4]
Unrealized Appreciation (Depreciation) 6,202,210us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_VixFuturesCboeExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember		 [4]
ProShares Ultra Bloomberg Crude Oil [Member]  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) (78,474,219)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraBloombergCrudeOilMember		 [5]
ProShares Ultra Bloomberg Crude Oil [Member] | Crude Oil - NYMEX, Expires May 2015 [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 13,821ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CrudeOilNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraBloombergCrudeOilMember		 [6]
Notional Amount at Value 657,879,600ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CrudeOilNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraBloombergCrudeOilMember		 [6]
Unrealized Appreciation (Depreciation) (63,863,441)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_CrudeOilNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraBloombergCrudeOilMember		 [6]
ProShares Ultra Bloomberg Natural Gas [Member] | Natural Gas-NYMEX, Expires May 2015 [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 4,644ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_NaturalGasNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraBloombergNaturalGasMember		 [7]
Notional Amount at Value 122,601,600ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_NaturalGasNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraBloombergNaturalGasMember		 [7]
Unrealized Appreciation (Depreciation) (7,437,631)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_NaturalGasNymexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraBloombergNaturalGasMember		 [7]
ProShares Ultra Gold [Member]  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) 1,660,968us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [5]
ProShares Ultra Gold [Member] | Gold Futures-COMEX, Expires June 2015 [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 2ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_GoldFuturesComexExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [8]
Notional Amount at Value 236,640ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_GoldFuturesComexExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [8]
Unrealized Appreciation (Depreciation) 6,020us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_GoldFuturesComexExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [8]
ProShares Ultra Silver [Member]  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) 22,620,868us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [5]
ProShares Ultra Silver [Member] | Silver Futures-COMEX, Expires May 2015 [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 2ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SilverFuturesComexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [9]
Notional Amount at Value 165,980ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SilverFuturesComexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [9]
Unrealized Appreciation (Depreciation) (3,320)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_SilverFuturesComexExpiresMayTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [9]
ProShares Ultra Australian Dollar [Member] | Australian Dollar Fx Currency Futures - CME, Expires June 2015 [Member] | Futures Contracts Purchased [Member]  
Schedule of Investments [Line Items]  
Number of Contracts 63ck0001415311_NumberOfContracts
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_AustralianDollarFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraAustralianDollarMember		 [10]
Notional Amount at Value 4,776,030ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_AustralianDollarFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraAustralianDollarMember		 [10]
Unrealized Appreciation (Depreciation) $ (57,414)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_DerivativeInstrumentRiskAxis
= ck0001415311_FuturesContractsPurchasedMember
/ us-gaap_InvestmentTypeAxis
= ck0001415311_AustralianDollarFxCurrencyFuturesCmeExpiresJuneTwoThousandAndFifteenMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraAustralianDollarMember		 [10]
[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 $11,020,165 was pledged to cover margin requirements for open futures contracts as of March 31, 2015.
[3] Cash collateral in the amount of $2,134,050 was pledged to cover margin requirements for open futures contracts as of March 31, 2015.
[4] Cash collateral in the amount of $73,653,370 was pledged to cover margin requirements for open futures contracts as of March 31, 2015.
[5] 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.
[6] Cash collateral in the amount of $13,420,311 was pledged to cover margin requirements for open futures contracts as of March 31, 2015.
[7] Cash collateral in the amount of $3,842,480 was pledged to cover margin requirements for open futures contracts as of March 31, 2015.
[8] Cash collateral in the amount of $8,800 was pledged to cover margin requirements for open futures contracts as of March 31, 2015.
[9] Cash collateral in the amount of $16,940 was pledged to cover margin requirements for open futures contracts as of March 31, 2015.
[10] Cash collateral in the amount of $152,460 was pledged to cover margin requirements for open futures contracts as of March 31, 2015.