Investments - Offsetting of Financial Assets and Liabilities (Detail) (USD $)	Mar. 31, 2015	Dec. 31, 2014
ProShares UltraShort Bloomberg Commodity [Member] \| Swap Agreements [Member]
Derivative [Line Items]
Gross Amounts of Recognized Assets presented in the Statements of Financial Condition	$ 276,625	$ 567,259
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amount	276,625	567,259
Gross Amounts Offset in the Statements of Financial Condition	0	0
ProShares UltraShort Bloomberg Crude Oil [Member] \| Swap Agreements [Member]
Derivative [Line Items]
Gross Amounts of Recognized Assets presented in the Statements of Financial Condition	26,857,473	27,018,077
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amount	26,857,473	27,018,077
Gross Amounts Offset in the Statements of Financial Condition	0	0
ProShares UltraShort Gold [Member] \| Forward Agreements [Member]
Derivative [Line Items]
Gross Amounts Offset in the Statements of Financial Condition	0	0
Gross Amounts of Recognized Liabilities presented in the Statements of Financial Condition	1,582,081	2,282,778
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amounts of Liabilities presented in the Statements of Financial Condition	1,582,081	2,282,778
ProShares UltraShort Silver [Member] \| Forward Agreements [Member]
Derivative [Line Items]
Gross Amounts of Recognized Assets presented in the Statements of Financial Condition		799,523
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amount		799,523
Gross Amounts of Recognized Liabilities presented in the Statements of Financial Condition	3,736,183	204,570
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amounts of Liabilities presented in the Statements of Financial Condition	3,736,183	204,570
ProShares UltraShort Euro [Member] \| Foreign Currency Forward Contracts [Member]
Derivative [Line Items]
Gross Amounts of Recognized Assets presented in the Statements of Financial Condition	25,478,862	19,019,765
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amount	25,478,862	19,019,765
Gross Amounts of Recognized Liabilities presented in the Statements of Financial Condition	2,088,667	2,256,771
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amounts of Liabilities presented in the Statements of Financial Condition	2,088,667	2,256,771
ProShares UltraShort Yen [Member] \| Foreign Currency Forward Contracts [Member]
Derivative [Line Items]
Gross Amounts of Recognized Assets presented in the Statements of Financial Condition	725,490	571,149
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amount	725,490	571,149
Gross Amounts of Recognized Liabilities presented in the Statements of Financial Condition	57,733	2,149,924
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amounts of Liabilities presented in the Statements of Financial Condition	57,733	2,149,924
ProShares Ultra Bloomberg Commodity [Member] \| Swap Agreements [Member]
Derivative [Line Items]
Gross Amounts Offset in the Statements of Financial Condition	0	0
Gross Amounts of Recognized Liabilities presented in the Statements of Financial Condition	129,433	331,338
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amounts of Liabilities presented in the Statements of Financial Condition	129,433	331,338
ProShares Ultra Bloomberg Crude Oil [Member] \| Swap Agreements [Member]
Derivative [Line Items]
Gross Amounts Offset in the Statements of Financial Condition	0	0
Gross Amounts of Recognized Liabilities presented in the Statements of Financial Condition	78,474,219	76,181,097
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amounts of Liabilities presented in the Statements of Financial Condition	78,474,219	76,181,097
ProShares Ultra Gold [Member] \| Forward Agreements [Member]
Derivative [Line Items]
Gross Amounts of Recognized Assets presented in the Statements of Financial Condition	1,660,968	2,051,154
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amount	1,660,968	2,051,154
Gross Amounts Offset in the Statements of Financial Condition	0	0
ProShares Ultra Silver [Member] \| Forward Agreements [Member]
Derivative [Line Items]
Gross Amounts of Recognized Assets presented in the Statements of Financial Condition	22,620,868
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amount	22,620,868
Gross Amounts of Recognized Liabilities presented in the Statements of Financial Condition		12,395,120
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amounts of Liabilities presented in the Statements of Financial Condition		12,395,120
ProShares Ultra Euro [Member] \| Foreign Currency Forward Contracts [Member]
Derivative [Line Items]
Gross Amounts of Recognized Assets presented in the Statements of Financial Condition	2,045	2,921
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amount	2,045	2,921
Gross Amounts of Recognized Liabilities presented in the Statements of Financial Condition	780,795	106,292
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amounts of Liabilities presented in the Statements of Financial Condition	780,795	106,292
ProShares Ultra Yen [Member] \| Foreign Currency Forward Contracts [Member]
Derivative [Line Items]
Gross Amounts of Recognized Assets presented in the Statements of Financial Condition		404
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amount		404
Gross Amounts of Recognized Liabilities presented in the Statements of Financial Condition	41,178	15,649
Gross Amounts Offset in the Statements of Financial Condition	0	0
Net Amounts of Liabilities presented in the Statements of Financial Condition	$ 41,178	$ 15,649

Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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