v2.4.1.9

Creation and Redemption of Creation Units - Schedule of Transaction Fees (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015
Creation And Redemption Of Creation Units [Line Items]
Transaction fees	$ 895,391ck0001415311_TransactionsFees
ProShares VIX Short-Term Futures ETF [Member]
Creation And Redemption Of Creation Units [Line Items]
Transaction fees	33,403ck0001415311_TransactionsFees / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesVixShortTermFuturesEtfMember
ProShares VIX Mid-Term Futures ETF [Member]
Creation And Redemption Of Creation Units [Line Items]
Transaction fees	5,138ck0001415311_TransactionsFees / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesVixMidTermFuturesEtfMember
ProShares Short VIX Short-Term Futures ETF [Member]
Creation And Redemption Of Creation Units [Line Items]
Transaction fees	61,292ck0001415311_TransactionsFees / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesShortVixShortTermFuturesEtfMember
ProShares Ultra VIX Short-Term Futures ETF [Member]
Creation And Redemption Of Creation Units [Line Items]
Transaction fees	336,970ck0001415311_TransactionsFees / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember
ProShares UltraShort Bloomberg Crude Oil [Member]
Creation And Redemption Of Creation Units [Line Items]
Transaction fees	131,659ck0001415311_TransactionsFees / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergCrudeOilMember
ProShares UltraShort Bloomberg Natural Gas [Member]
Creation And Redemption Of Creation Units [Line Items]
Transaction fees	2,813ck0001415311_TransactionsFees / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergNaturalGasMember
ProShares UltraShort Gold [Member]
Creation And Redemption Of Creation Units [Line Items]
Transaction fees	5,246ck0001415311_TransactionsFees / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortGoldMember
ProShares UltraShort Silver [Member]
Creation And Redemption Of Creation Units [Line Items]
Transaction fees	9,000ck0001415311_TransactionsFees / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortSilverMember
ProShares Ultra Bloomberg Crude Oil [Member]
Creation And Redemption Of Creation Units [Line Items]
Transaction fees	293,240ck0001415311_TransactionsFees / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCrudeOilMember
ProShares Ultra Bloomberg Natural Gas [Member]
Creation And Redemption Of Creation Units [Line Items]
Transaction fees	4,663ck0001415311_TransactionsFees / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergNaturalGasMember
ProShares Ultra Gold [Member]
Creation And Redemption Of Creation Units [Line Items]
Transaction fees	1,459ck0001415311_TransactionsFees / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraGoldMember
ProShares Ultra Silver [Member]
Creation And Redemption Of Creation Units [Line Items]
Transaction fees	$ 10,508ck0001415311_TransactionsFees / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraSilverMember

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