v2.4.1.9
Schedule of Investments - Forward Agreements (Detail) (USD $)
 3 Months Ended
Mar. 31, 2015
ProShares UltraShort Gold [Member]  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) $ (1,582,081)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1]
ProShares UltraShort Gold [Member] | Forward Agreements with Deutsche Bank AG Based on 0.995 Fine Troy Ounce Gold [Member]  
Schedule of Investments [Line Items]  
Rate Paid (Received) 0.14%ck0001415311_DerivativeRateReceivedPaidPercent
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithDeutscheBankAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1],[2]
Settlement Date Apr. 07, 2015 [1]
Commitment to (Deliver)/Receive (63,900)ck0001415311_CommitmentToDeliverReceive
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithDeutscheBankAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1]
Notional Amount at Value (75,851,856)ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithDeutscheBankAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1],[3]
Unrealized Appreciation (Depreciation) (647,913)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithDeutscheBankAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1]
ProShares UltraShort Gold [Member] | Forward Agreements with Goldman Sachs International Based on 0.995 Fine Troy Ounce Gold [Member]  
Schedule of Investments [Line Items]  
Rate Paid (Received) 0.28%ck0001415311_DerivativeRateReceivedPaidPercent
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1],[2]
Settlement Date Apr. 07, 2015 [1]
Commitment to (Deliver)/Receive (28,898)ck0001415311_CommitmentToDeliverReceive
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1]
Notional Amount at Value (34,302,793)ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1],[3]
Unrealized Appreciation (Depreciation) (370,015)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1]
ProShares UltraShort Gold [Member] | Forward Agreements with Societe Generale S.A. Based on 0.995 Fine Troy Ounce Gold [Member]  
Schedule of Investments [Line Items]  
Rate Paid (Received) 0.40%ck0001415311_DerivativeRateReceivedPaidPercent
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithSocieteGeneraleSaBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1],[2]
Settlement Date Apr. 07, 2015 [1]
Commitment to (Deliver)/Receive (13,100)ck0001415311_CommitmentToDeliverReceive
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithSocieteGeneraleSaBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1]
Notional Amount at Value (15,549,962)ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithSocieteGeneraleSaBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1],[3]
Unrealized Appreciation (Depreciation) (375,583)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithSocieteGeneraleSaBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1]
ProShares UltraShort Gold [Member] | Forward Agreements with UBS AG Based on 0.995 Fine Troy Ounce Gold [Member]  
Schedule of Investments [Line Items]  
Rate Paid (Received) 0.29%ck0001415311_DerivativeRateReceivedPaidPercent
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1],[2]
Settlement Date Apr. 07, 2015 [1]
Commitment to (Deliver)/Receive (25,250)ck0001415311_CommitmentToDeliverReceive
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1]
Notional Amount at Value (29,972,508)ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1],[3]
Unrealized Appreciation (Depreciation) (188,570)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortGoldMember		 [1]
ProShares UltraShort Silver [Member]  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) (3,736,183)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1]
ProShares UltraShort Silver [Member] | Forward Agreements with Deutsche Bank AG Based on 0.999 Fine Troy Ounce Silver [Member]  
Schedule of Investments [Line Items]  
Rate Paid (Received) (0.27%)ck0001415311_DerivativeRateReceivedPaidPercent
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithDeutscheBankAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1],[2]
Settlement Date Apr. 07, 2015 [1]
Commitment to (Deliver)/Receive (3,059,000)ck0001415311_CommitmentToDeliverReceive
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithDeutscheBankAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1]
Notional Amount at Value (50,784,906)ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithDeutscheBankAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1],[3]
Unrealized Appreciation (Depreciation) (1,877,505)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithDeutscheBankAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1]
ProShares UltraShort Silver [Member] | Forward Agreements with Goldman Sachs International Based on 0.999 Fine Troy Ounce Silver [Member]  
Schedule of Investments [Line Items]  
Rate Paid (Received) 0.00%ck0001415311_DerivativeRateReceivedPaidPercent
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1],[2]
Settlement Date Apr. 07, 2015 [1]
Commitment to (Deliver)/Receive (1,595,500)ck0001415311_CommitmentToDeliverReceive
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1]
Notional Amount at Value (26,487,374)ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1],[3]
Unrealized Appreciation (Depreciation) (860,699)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1]
ProShares UltraShort Silver [Member] | Forward Agreements with Societe Generale S.A. Based on 0.999 Fine Troy Ounce Silver [Member]  
Schedule of Investments [Line Items]  
Rate Paid (Received) (0.01%)ck0001415311_DerivativeRateReceivedPaidPercent
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithSocieteGeneraleSaBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1],[2]
Settlement Date Apr. 07, 2015 [1]
Commitment to (Deliver)/Receive (547,000)ck0001415311_CommitmentToDeliverReceive
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithSocieteGeneraleSaBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1]
Notional Amount at Value (9,081,075)ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithSocieteGeneraleSaBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1],[3]
Unrealized Appreciation (Depreciation) (296,399)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithSocieteGeneraleSaBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1]
ProShares UltraShort Silver [Member] | Forward Agreements with UBS AG Based on 0.999 Fine Troy Ounce Silver [Member]  
Schedule of Investments [Line Items]  
Rate Paid (Received) (0.05%)ck0001415311_DerivativeRateReceivedPaidPercent
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1],[2]
Settlement Date Apr. 07, 2015 [1]
Commitment to (Deliver)/Receive (1,595,000)ck0001415311_CommitmentToDeliverReceive
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1]
Notional Amount at Value (26,479,552)ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1],[3]
Unrealized Appreciation (Depreciation) (701,580)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltrashortSilverMember		 [1]
ProShares Ultra Gold [Member]  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) 1,660,968us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1]
ProShares Ultra Gold [Member] | Forward Agreements with Deutsche Bank AG Based on 0.995 Fine Troy Ounce Gold [Member]  
Schedule of Investments [Line Items]  
Rate Paid (Received) 0.46%ck0001415311_DerivativeRateReceivedPaidPercent
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithDeutscheBankAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1],[2]
Settlement Date Apr. 07, 2015 [1]
Commitment to (Deliver)/Receive 82,300ck0001415311_CommitmentToDeliverReceive
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithDeutscheBankAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1]
Notional Amount at Value 97,693,392ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithDeutscheBankAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1],[3]
Unrealized Appreciation (Depreciation) 895,425us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithDeutscheBankAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1]
ProShares Ultra Gold [Member] | Forward Agreements with Goldman Sachs International Based on 0.995 Fine Troy Ounce Gold [Member]  
Schedule of Investments [Line Items]  
Rate Paid (Received) 0.57%ck0001415311_DerivativeRateReceivedPaidPercent
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1],[2]
Settlement Date Apr. 07, 2015 [1]
Commitment to (Deliver)/Receive 33,320ck0001415311_CommitmentToDeliverReceive
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1]
Notional Amount at Value 39,551,840ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1],[3]
Unrealized Appreciation (Depreciation) 346,843us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1]
ProShares Ultra Gold [Member] | Forward Agreements with Societe Generale S.A. Based on 0.995 Fine Troy Ounce Gold [Member]  
Schedule of Investments [Line Items]  
Rate Paid (Received) 0.60%ck0001415311_DerivativeRateReceivedPaidPercent
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithSocieteGeneraleSaBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1],[2]
Settlement Date Apr. 07, 2015 [1]
Commitment to (Deliver)/Receive 15,900ck0001415311_CommitmentToDeliverReceive
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithSocieteGeneraleSaBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1]
Notional Amount at Value 18,873,618ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithSocieteGeneraleSaBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1],[3]
Unrealized Appreciation (Depreciation) 90,113us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithSocieteGeneraleSaBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1]
ProShares Ultra Gold [Member] | Forward Agreements with UBS AG Based on 0.995 Fine Troy Ounce Gold [Member]  
Schedule of Investments [Line Items]  
Rate Paid (Received) 0.51%ck0001415311_DerivativeRateReceivedPaidPercent
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1],[2]
Settlement Date Apr. 07, 2015 [1]
Commitment to (Deliver)/Receive 29,900ck0001415311_CommitmentToDeliverReceive
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1]
Notional Amount at Value 35,492,197ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1],[3]
Unrealized Appreciation (Depreciation) 328,587us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineFiveFineTroyOunceGoldMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraGoldMember		 [1]
ProShares Ultra Silver [Member]  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) 22,620,868us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1]
ProShares Ultra Silver [Member] | Forward Agreements with Deutsche Bank AG Based on 0.999 Fine Troy Ounce Silver [Member]  
Schedule of Investments [Line Items]  
Rate Paid (Received) 0.87%ck0001415311_DerivativeRateReceivedPaidPercent
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithDeutscheBankAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1],[2]
Settlement Date Apr. 07, 2015 [1]
Commitment to (Deliver)/Receive 19,287,000ck0001415311_CommitmentToDeliverReceive
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithDeutscheBankAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1]
Notional Amount at Value 320,198,917ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithDeutscheBankAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1],[3]
Unrealized Appreciation (Depreciation) 12,075,006us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithDeutscheBankAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1]
ProShares Ultra Silver [Member] | Forward Agreements with Goldman Sachs International Based on 0.999 Fine Troy Ounce Silver [Member]  
Schedule of Investments [Line Items]  
Rate Paid (Received) 0.85%ck0001415311_DerivativeRateReceivedPaidPercent
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1],[2]
Settlement Date Apr. 07, 2015 [1]
Commitment to (Deliver)/Receive 7,302,800ck0001415311_CommitmentToDeliverReceive
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1]
Notional Amount at Value 121,235,974ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1],[3]
Unrealized Appreciation (Depreciation) 4,343,236us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithGoldmanSachsInternationalBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1]
ProShares Ultra Silver [Member] | Forward Agreements with Societe Generale S.A. Based on 0.999 Fine Troy Ounce Silver [Member]  
Schedule of Investments [Line Items]  
Rate Paid (Received) 1.01%ck0001415311_DerivativeRateReceivedPaidPercent
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithSocieteGeneraleSaBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1],[2]
Settlement Date Apr. 07, 2015 [1]
Commitment to (Deliver)/Receive 4,255,000ck0001415311_CommitmentToDeliverReceive
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithSocieteGeneraleSaBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1]
Notional Amount at Value 70,639,808ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithSocieteGeneraleSaBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1],[3]
Unrealized Appreciation (Depreciation) 2,548,949us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithSocieteGeneraleSaBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1]
ProShares Ultra Silver [Member] | Forward Agreements with UBS AG Based on 0.999 Fine Troy Ounce Silver [Member]  
Schedule of Investments [Line Items]  
Rate Paid (Received) 0.95%ck0001415311_DerivativeRateReceivedPaidPercent
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1],[2]
Settlement Date Apr. 07, 2015 [1]
Commitment to (Deliver)/Receive 7,355,000ck0001415311_CommitmentToDeliverReceive
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1]
Notional Amount at Value 122,104,768ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1],[3]
Unrealized Appreciation (Depreciation) $ 3,653,677us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
/ us-gaap_InvestmentTypeAxis
= ck0001415311_ForwardAgreementsWithUbsAgBasedOnZeroPointNineNineNineFineTroyOunceSilverMember
/ us-gaap_StatementBusinessSegmentsAxis
= ck0001415311_ProsharesUltraSilverMember		 [1]
[1] 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.
[2] Reflects the floating financing rate, as of March 31, 2015, on the notional amount of the forward agreement paid to the counterparty or received from the counterparty, excluding any commissions.
[3] For forward agreements, a positive amount represents "long" exposure to the underlying commodity. A negative amount represents "short" exposure to the underlying commodity.