v2.4.1.9

Statements of Financial Condition (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
ProShares VIX Short-Term Futures ETF [Member]
Short-term U.S. government and agency obligations, cost	$ 131,183,329ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesVixShortTermFuturesEtfMember	$ 82,086,464ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesVixShortTermFuturesEtfMember
ProShares VIX Mid-Term Futures ETF [Member]
Short-term U.S. government and agency obligations, cost	27,674,827ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesVixMidTermFuturesEtfMember	24,104,754ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesVixMidTermFuturesEtfMember
ProShares Short VIX Short-Term Futures ETF [Member]
Short-term U.S. government and agency obligations, cost	222,916,842ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesShortVixShortTermFuturesEtfMember	446,972,637ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesShortVixShortTermFuturesEtfMember
ProShares Ultra VIX Short-Term Futures ETF [Member]
Short-term U.S. government and agency obligations, cost	569,902,127ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember	182,641,263ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember
ProShares UltraShort Bloomberg Commodity [Member]
Short-term U.S. government and agency obligations, cost	4,990,615ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergCommodityMember	4,233,396ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergCommodityMember
ProShares UltraShort Bloomberg Crude Oil [Member]
Short-term U.S. government and agency obligations, cost	319,738,023ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergCrudeOilMember	131,592,367ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergCrudeOilMember
ProShares UltraShort Bloomberg Natural Gas [Member]
Short-term U.S. government and agency obligations, cost	8,979,490ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergNaturalGasMember	8,672,527ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortBloombergNaturalGasMember
ProShares UltraShort Gold [Member]
Short-term U.S. government and agency obligations, cost	79,438,253ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortGoldMember	84,038,905ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortGoldMember
ProShares UltraShort Silver [Member]
Short-term U.S. government and agency obligations, cost	50,000,423ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortSilverMember	52,225,712ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortSilverMember
ProShares Short Euro [Member]
Short-term U.S. government and agency obligations, cost	18,011,817ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesShortEuroMember	12,086,398ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesShortEuroMember
ProShares UltraShort Australian Dollar [Member]
Short-term U.S. government and agency obligations, cost	16,932,386ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortAustralianDollarMember	20,267,681ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortAustralianDollarMember
ProShares UltraShort Euro [Member]
Short-term U.S. government and agency obligations, cost	549,433,835ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember	487,097,789ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortEuroMember
ProShares UltraShort Yen [Member]
Short-term U.S. government and agency obligations, cost	444,086,152ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember	532,944,509ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltrashortYenMember
ProShares Ultra Bloomberg Commodity [Member]
Short-term U.S. government and agency obligations, cost	2,242,745ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCommodityMember	2,754,883ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCommodityMember
ProShares Ultra Bloomberg Crude Oil [Member]
Short-term U.S. government and agency obligations, cost	1,066,107,943ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCrudeOilMember	467,195,638ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCrudeOilMember
ProShares Ultra Bloomberg Natural Gas [Member]
Short-term U.S. government and agency obligations, cost	57,169,151ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergNaturalGasMember	53,408,848ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergNaturalGasMember
ProShares Ultra Gold [Member]
Short-term U.S. government and agency obligations, cost	94,231,992ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraGoldMember	101,925,636ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraGoldMember
ProShares Ultra Silver [Member]
Short-term U.S. government and agency obligations, cost	294,492,151ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraSilverMember	305,465,636ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraSilverMember
ProShares Ultra Australian Dollar [Member]
Short-term U.S. government and agency obligations, cost	2,201,929ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraAustralianDollarMember	2,405,682ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraAustralianDollarMember
ProShares Ultra Euro [Member]
Short-term U.S. government and agency obligations, cost	15,242,859ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember	2,415,732ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraEuroMember
ProShares Ultra Yen [Member]
Short-term U.S. government and agency obligations, cost	5,210,360ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember	1,287,844ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember
ProShares Trust II [Member]
Short-term U.S. government and agency obligations, cost	$ 3,980,187,249ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesTrustIiMember	$ 3,005,824,301ck0001415311_ShortTermUSGovernmentAndAgencyObligationsCost / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesTrustIiMember

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