v2.4.1.9

Schedule of Investments - Foreign Currency Forward Contracts (Detail) (USD $) | 3 Months Ended
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Mar. 31, 2015
ProShares UltraShort Euro [Member] | Contracts to Purchase [Member] |  |
Schedule of Investments [Line Items] |  |
Unrealized Appreciation (Depreciation) | $ (2,088,667)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember | [1]
ProShares UltraShort Euro [Member] | Contracts to Purchase [Member] | Euro with Goldman Sachs International [Member] |  |
Schedule of Investments [Line Items] |  |
Settlement Date | Apr. 10, 2015 | [1]
Local Currency | 81,791,800 ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember | [1]
Notional Amount at Value | 87,926,805 ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember | [1]
Unrealized Appreciation (Depreciation) | (886,380)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember | [1]
ProShares UltraShort Euro [Member] | Contracts to Purchase [Member] | Euro with UBS AG [Member] |  |
Schedule of Investments [Line Items] |  |
Settlement Date | Apr. 10, 2015 | [1]
Local Currency | 110,930,600 ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember | [1]
Notional Amount at Value | 119,251,236 ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember | [1]
Unrealized Appreciation (Depreciation) | (1,202,287)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember | [1]
ProShares UltraShort Euro [Member] | Contracts to Sell [Member] |  |
Schedule of Investments [Line Items] |  |
Unrealized Appreciation (Depreciation) | 25,478,862 us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember | [1]
ProShares UltraShort Euro [Member] | Contracts to Sell [Member] | Euro with Goldman Sachs International [Member] |  |
Schedule of Investments [Line Items] |  |
Settlement Date | Apr. 10, 2015 | [1]
Local Currency | (617,582,525)ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember | [1]
Notional Amount at Value | (663,905,895)ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember | [1]
Unrealized Appreciation (Depreciation) | 11,962,630 us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember | [1]
ProShares UltraShort Euro [Member] | Contracts to Sell [Member] | Euro with UBS AG [Member] |  |
Schedule of Investments [Line Items] |  |
Settlement Date | Apr. 10, 2015 | [1]
Local Currency | (728,286,800)ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember | [1]
Notional Amount at Value | (782,913,830)ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember | [1]
Unrealized Appreciation (Depreciation) | 13,516,232 us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember | [1]
ProShares UltraShort Yen [Member] | Contracts to Purchase [Member] |  |
Schedule of Investments [Line Items] |  |
Unrealized Appreciation (Depreciation) | (22,026)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember | [1]
ProShares UltraShort Yen [Member] | Contracts to Purchase [Member] | Yen with Goldman Sachs International [Member] |  |
Schedule of Investments [Line Items] |  |
Settlement Date | Apr. 10, 2015 | [1]
Local Currency | 20,565,620,300 ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember | [1]
Notional Amount at Value | 171,495,639 ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember | [1]
Unrealized Appreciation (Depreciation) | 35,707 us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember | [1]
ProShares UltraShort Yen [Member] | Contracts to Purchase [Member] | Yen with UBS AG [Member] |  |
Schedule of Investments [Line Items] |  |
Settlement Date | Apr. 10, 2015 | [1]
Local Currency | 5,923,386,600 ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember | [1]
Notional Amount at Value | 49,394,813 ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember | [1]
Unrealized Appreciation (Depreciation) | (57,733)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember | [1]
ProShares UltraShort Yen [Member] | Contracts to Sell [Member] |  |
Schedule of Investments [Line Items] |  |
Unrealized Appreciation (Depreciation) | 689,783 us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember | [1]
ProShares UltraShort Yen [Member] | Contracts to Sell [Member] | Yen with Goldman Sachs International [Member] |  |
Schedule of Investments [Line Items] |  |
Settlement Date | Apr. 10, 2015 | [1]
Local Currency | (68,851,569,600)ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember | [1]
Notional Amount at Value | (574,149,660)ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember | [1]
Unrealized Appreciation (Depreciation) | 410,985 us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember | [1]
ProShares UltraShort Yen [Member] | Contracts to Sell [Member] | Yen with UBS AG [Member] |  |
Schedule of Investments [Line Items] |  |
Settlement Date | Apr. 10, 2015 | [1]
Local Currency | (63,324,691,700)ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember | [1]
Notional Amount at Value | (528,061,312)ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember | [1]
Unrealized Appreciation (Depreciation) | 278,798 us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember | [1]
ProShares Ultra Euro [Member] | Contracts to Purchase [Member] |  |
Schedule of Investments [Line Items] |  |
Unrealized Appreciation (Depreciation) | (776,591)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember | [1]
ProShares Ultra Euro [Member] | Contracts to Purchase [Member] | Euro with Goldman Sachs International [Member] |  |
Schedule of Investments [Line Items] |  |
Settlement Date | Apr. 10, 2015 | [1]
Local Currency | 15,842,925 ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember | [1]
Notional Amount at Value | 17,031,264 ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember | [1]
Unrealized Appreciation (Depreciation) | (356,825)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember | [1]
ProShares Ultra Euro [Member] | Contracts to Purchase [Member] | Euro with UBS AG [Member] |  |
Schedule of Investments [Line Items] |  |
Settlement Date | Apr. 10, 2015 | [1]
Local Currency | 14,064,800 ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember | [1]
Notional Amount at Value | 15,119,767 ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember | [1]
Unrealized Appreciation (Depreciation) | (419,766)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember | [1]
ProShares Ultra Euro [Member] | Contracts to Sell [Member] |  |
Schedule of Investments [Line Items] |  |
Unrealized Appreciation (Depreciation) | (2,159)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember | [1]
ProShares Ultra Euro [Member] | Contracts to Sell [Member] | Euro with Goldman Sachs International [Member] |  |
Schedule of Investments [Line Items] |  |
Settlement Date | Apr. 10, 2015 | [1]
Local Currency | (1,344,700)ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember | [1]
Notional Amount at Value | (1,445,563)ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember | [1]
Unrealized Appreciation (Depreciation) | (4,204)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember | [1]
ProShares Ultra Euro [Member] | Contracts to Sell [Member] | Euro with UBS AG [Member] |  |
Schedule of Investments [Line Items] |  |
Settlement Date | Apr. 10, 2015 | [1]
Local Currency | (1,092,000)ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember | [1]
Notional Amount at Value | (1,173,908)ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember | [1]
Unrealized Appreciation (Depreciation) | 2,045 us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember | [1]
ProShares Ultra Yen [Member] | Contracts to Purchase [Member] |  |
Schedule of Investments [Line Items] |  |
Unrealized Appreciation (Depreciation) | (25,954)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember | [1]
ProShares Ultra Yen [Member] | Contracts to Purchase [Member] | Yen with Goldman Sachs International [Member] |  |
Schedule of Investments [Line Items] |  |
Settlement Date | Apr. 10, 2015 | [1]
Local Currency | 898,339,400 ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember | [1]
Notional Amount at Value | 7,491,206 ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember | [1]
Unrealized Appreciation (Depreciation) | (14,944)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember | [1]
ProShares Ultra Yen [Member] | Contracts to Purchase [Member] | Yen with UBS AG [Member] |  |
Schedule of Investments [Line Items] |  |
Settlement Date | Apr. 10, 2015 | [1]
Local Currency | 645,732,000 ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember | [1]
Notional Amount at Value | 5,384,726 ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember | [1]
Unrealized Appreciation (Depreciation) | (11,010)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember | [1]
ProShares Ultra Yen [Member] | Contracts to Sell [Member] |  |
Schedule of Investments [Line Items] |  |
Unrealized Appreciation (Depreciation) | (15,224)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember | [1]
ProShares Ultra Yen [Member] | Contracts to Sell [Member] | Yen with Goldman Sachs International [Member] |  |
Schedule of Investments [Line Items] |  |
Settlement Date | Apr. 10, 2015 | [1]
Local Currency | (17,456,500)ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember | [1]
Notional Amount at Value | (145,569)ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember | [1]
Unrealized Appreciation (Depreciation) | (661)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember | [1]
ProShares Ultra Yen [Member] | Contracts to Sell [Member] | Yen with UBS AG [Member] |  |
Schedule of Investments [Line Items] |  |
Settlement Date | Apr. 10, 2015 | [1]
Local Currency | (185,698,000)ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember | [1]
Notional Amount at Value | (1,548,526)ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember | [1]
Unrealized Appreciation (Depreciation) | $ (14,563)us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet / invest_InvestmentAxis = ck0001415311_ContractsToSellMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember | [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.

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