v2.4.1.9

Schedule of Investments - Foreign Currency Forward Contracts (Detail) (USD $)	3 Months Ended
	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	81,791,800ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember	[1]
Notional Amount at Value	87,926,805ck0001415311_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	110,930,600ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember	[1]
Notional Amount at Value	119,251,236ck0001415311_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)	25,478,862us-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)	11,962,630us-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)	13,516,232us-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	20,565,620,300ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember	[1]
Notional Amount at Value	171,495,639ck0001415311_LongShortInvestmentOwnedUnderlyingFaceAmountAtMarketValue / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember	[1]
Unrealized Appreciation (Depreciation)	35,707us-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	5,923,386,600ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember	[1]
Notional Amount at Value	49,394,813ck0001415311_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)	689,783us-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)	410,985us-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)	278,798us-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	15,842,925ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember	[1]
Notional Amount at Value	17,031,264ck0001415311_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	14,064,800ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_EuroWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember	[1]
Notional Amount at Value	15,119,767ck0001415311_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)	2,045us-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	898,339,400ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithGoldmanSachsInternationalMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember	[1]
Notional Amount at Value	7,491,206ck0001415311_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	645,732,000ck0001415311_LocalCurrency / invest_InvestmentAxis = ck0001415311_ContractsToPurchaseMember / us-gaap_InvestmentTypeAxis = ck0001415311_YenWithUbsAgMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember	[1]
Notional Amount at Value	5,384,726ck0001415311_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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- Definition

Long (Short) Investment Owned Underlying Face Amount at Market Value

+ References

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- Definition

This element represents the net excess or deficiency of the fair value of an investment (security, contract) over or under its cost (face amount, notional amount), respectively, which excess value or deficiency has not been recognized in earnings of the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 946

-SubTopic 320

-Section S99

-Paragraph 22

-URI http://asc.fasb.org/extlink&oid=34726532&loc=SL6090603-123010

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