v2.4.1.9

Investments - Effect of Derivative Instruments on Statements of Operations (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain or (Loss) on Derivatives Recognized in Income	$ (203,646,363)us-gaap_DerivativeGainLossOnDerivativeNet	$ 76,214,916us-gaap_DerivativeGainLossOnDerivativeNet
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income	(32,673,514)ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome	(53,072,999)ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome
Managed Futures Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts [Member] | ProShares Managed Futures Strategy [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain or (Loss) on Derivatives Recognized in Income	119,252us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = ck0001415311_FuturesContractsMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesManagedFuturesStrategyMember
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income	(21,094)ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = ck0001415311_FuturesContractsMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesManagedFuturesStrategyMember
VIX Futures Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts [Member] | ProShares VIX Short-Term Futures ETF [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain or (Loss) on Derivatives Recognized in Income	(8,978,330)us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_FutureMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesVixShortTermFuturesEtfMember	15,779,707us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_FutureMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesVixShortTermFuturesEtfMember
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income	(11,370,731)ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_FutureMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesVixShortTermFuturesEtfMember	11,625,721ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_FutureMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesVixShortTermFuturesEtfMember
VIX Futures Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts [Member] | ProShares VIX Mid-Term Futures ETF [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain or (Loss) on Derivatives Recognized in Income	126,671us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_FutureMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesVixMidTermFuturesEtfMember	(5,397,902)us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_FutureMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesVixMidTermFuturesEtfMember
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income	(761,055)ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_FutureMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesVixMidTermFuturesEtfMember	2,889,479ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_FutureMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesVixMidTermFuturesEtfMember
VIX Futures Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts [Member] | ProShares Short VIX Short-Term Futures ETF [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain or (Loss) on Derivatives Recognized in Income	23,811,285us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_FutureMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesShortVixShortTermFuturesEtfMember	2,731,436us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_FutureMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesShortVixShortTermFuturesEtfMember
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income	23,344,133ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_FutureMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesShortVixShortTermFuturesEtfMember	(33,756)ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_FutureMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesShortVixShortTermFuturesEtfMember
VIX Futures Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts/ Changes in Unrealized Appreciation/ Depreciation on Futures Contracts [Member] | ProShares Ultra VIX Short-Term Futures ETF [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain or (Loss) on Derivatives Recognized in Income	(135,093,226)us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_FutureMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember	(3,546,304)us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_FutureMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income	(88,510,946)ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_FutureMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember	(5,691,916)ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_FutureMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/or Forward Agreements/Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/or Forward Agreements [Member] | ProShares UltraShort Bloomberg Commodity [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain or (Loss) on Derivatives Recognized in Income	856,549us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergCommodityMember	(635,695)us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergCommodityMember
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income	(290,634)ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergCommodityMember	129,934ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergCommodityMember
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/or Forward Agreements/Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/or Forward Agreements [Member] | ProShares UltraShort Bloomberg Crude Oil [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain or (Loss) on Derivatives Recognized in Income	44,649,872us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergCrudeOilMember	(12,278,001)us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergCrudeOilMember
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income	1,439,054ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergCrudeOilMember	(3,391,572)ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergCrudeOilMember
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/or Forward Agreements/Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/or Forward Agreements [Member] | ProShares UltraShort Bloomberg Natural Gas [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain or (Loss) on Derivatives Recognized in Income	5,179,268us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergNaturalGasMember	(9,215,034)us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergNaturalGasMember
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income	(3,081,725)ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergNaturalGasMember	3,437,020ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergNaturalGasMember
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/or Forward Agreements/Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/or Forward Agreements [Member] | ProShares UltraShort Gold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain or (Loss) on Derivatives Recognized in Income	1,918,530us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortGoldMember	(22,149,687)us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortGoldMember
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income	699,177ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortGoldMember	2,901,049ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortGoldMember
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/or Forward Agreements/Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/or Forward Agreements [Member] | ProShares UltraShort Silver [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain or (Loss) on Derivatives Recognized in Income	(1,361,705)us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortSilverMember	(12,614,405)us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortSilverMember
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income	(4,329,601)ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortSilverMember	9,961,567ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortSilverMember
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/or Forward Agreements/Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/or Forward Agreements [Member] | ProShares Ultra Bloomberg Commodity [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain or (Loss) on Derivatives Recognized in Income	(520,459)us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCommodityMember	537,342us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCommodityMember
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income	201,905ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCommodityMember	(129,206)ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCommodityMember
Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/or Forward Agreements/Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/or Forward Agreements [Member] | ProShares Ultra Bloomberg Crude Oil [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized Gain or (Loss) on Derivatives Recognized in Income	(173,683,119)us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCrudeOilMember	21,193,668us-gaap_DerivativeGainLossOnDerivativeNet / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCrudeOilMember
Change in Unrealized Appreciation or Depreciation on Derivatives Recognized in Income	(19,681,776)ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCrudeOilMember	484,711ck0001415311_ChangeInUnrealizedAppreciationDepreciationOnDerivativesRecognizedInIncome / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_IncomeStatementLocationAxis = ck0001415311_NetRealizedGainLossOnFuturesContractsSwapAndOrForwardAgreementsChangesInUnrealizedAppreciationDepreciationOnFuturesContractsSwapAndOrForwardAgreementsMember / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCrudeOilMember
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Derivative Instruments, Gain (Loss) [Line Items]
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Derivative Instruments, Gain (Loss) [Line Items]
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Commodity Contracts [Member] | Net Realized Gain (Loss) on Futures Contracts, Swap and/or Forward Agreements/Changes in Unrealized Appreciation/ Depreciation on Futures Contracts, Swap and/or Forward Agreements [Member] | ProShares Ultra Silver [Member]
Derivative Instruments, Gain (Loss) [Line Items]
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Foreign Exchange Contracts [Member] | Net Realized Gain (Loss) on Futures and/or Foreign Currency Forward Contracts/Changes in Unrealized Appreciation/ Depreciation on Futures and/or Foreign Currency Forward Contracts [Member] | ProShares Short Euro [Member]
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+ References

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

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