v3.10.0.1
Investments - Gross Amounts Not Offset in Statements of Financial Condition (Detail) - USD ($)
Jun. 30, 2018
Dec. 31, 2017
ProShares Ultra Bloomberg Crude Oil [Member] | Goldman Sachs International [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition $ 21,365,763 $ 16,654,031
Financial Instruments for the Benefit of (the Funds) / the Counterparties (20,159,696) (14,861,090)
Net Amounts of Assets presented in the Statements of Financial Condition 1,206,067 1,792,941
ProShares Ultra Bloomberg Crude Oil [Member] | UBS AG [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 21,864,163 16,764,919
Financial Instruments for the Benefit of (the Funds) / the Counterparties (20,658,539) (15,477,566)
Net Amounts of Assets presented in the Statements of Financial Condition 1,205,624 1,287,353
ProShares Ultra Bloomberg Crude Oil [Member] | Citibank N.A. [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 29,027,266 19,815,892
Net Amounts of Assets presented in the Statements of Financial Condition 29,027,266 19,815,892
ProShares Ultra Bloomberg Crude Oil [Member] | Societe Generale S.A. [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 8,999,126 9,003,519
Financial Instruments for the Benefit of (the Funds) / the Counterparties (8,942,433) (8,525,505)
Net Amounts of Assets presented in the Statements of Financial Condition 56,693 478,014
ProShares Ultra Bloomberg Crude Oil [Member] | RBC. NA [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 1,172,552  
Net Amounts of Assets presented in the Statements of Financial Condition 1,172,552  
ProShares Ultra Euro [Member] | Goldman Sachs International [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition   102,424
Net Amounts of Assets presented in the Statements of Financial Condition   102,424
Amounts of Recognized Assets presented in the Statements of Financial Condition (77,986)  
Cash Collateral for the Benefit of (the Funds) / the Counterparties 77,986  
ProShares Ultra Euro [Member] | UBS AG [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition   161,728
Net Amounts of Assets presented in the Statements of Financial Condition   161,728
Amounts of Recognized Assets presented in the Statements of Financial Condition (94,068)  
Cash Collateral for the Benefit of (the Funds) / the Counterparties 94,068  
ProShares Ultra Gold [Member] | Goldman Sachs International [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition   969,501
Financial Instruments for the Benefit of (the Funds) / the Counterparties   (967,678)
Cash Collateral for the Benefit of (the Funds) / the Counterparties   (1,823)
Amounts of Recognized Assets presented in the Statements of Financial Condition (1,977,494)  
Financial Instruments for the Benefit of (the Funds) / the Counterparties 1,977,494  
ProShares Ultra Gold [Member] | UBS AG [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition   945,225
Financial Instruments for the Benefit of (the Funds) / the Counterparties   (945,225)
Amounts of Recognized Assets presented in the Statements of Financial Condition (1,952,388)  
Financial Instruments for the Benefit of (the Funds) / the Counterparties 1,952,388  
ProShares Ultra Gold [Member] | Citibank N.A. [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition   1,513,310
Net Amounts of Assets presented in the Statements of Financial Condition   1,513,310
Amounts of Recognized Assets presented in the Statements of Financial Condition (2,546,835)  
Financial Instruments for the Benefit of (the Funds) / the Counterparties 2,546,835  
ProShares Ultra Gold [Member] | Societe Generale S.A. [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition   218,319
Net Amounts of Assets presented in the Statements of Financial Condition   218,319
Amounts of Recognized Assets presented in the Statements of Financial Condition (676,179)  
Financial Instruments for the Benefit of (the Funds) / the Counterparties 676,179  
ProShares Ultra Silver [Member] | Goldman Sachs International [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition   5,873,080
Financial Instruments for the Benefit of (the Funds) / the Counterparties   (4,903,696)
Net Amounts of Assets presented in the Statements of Financial Condition   969,384
Amounts of Recognized Assets presented in the Statements of Financial Condition (4,075,705)  
Financial Instruments for the Benefit of (the Funds) / the Counterparties 732,705  
Cash Collateral for the Benefit of (the Funds) / the Counterparties 3,343,000  
ProShares Ultra Silver [Member] | UBS AG [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition   5,898,693
Financial Instruments for the Benefit of (the Funds) / the Counterparties   (4,930,596)
Net Amounts of Assets presented in the Statements of Financial Condition   968,097
Amounts of Recognized Assets presented in the Statements of Financial Condition (3,722,182)  
Financial Instruments for the Benefit of (the Funds) / the Counterparties 3,722,182  
ProShares Ultra Silver [Member] | Citibank N.A. [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition   7,201,744
Net Amounts of Assets presented in the Statements of Financial Condition   7,201,744
Amounts of Recognized Assets presented in the Statements of Financial Condition (4,560,857)  
Cash Collateral for the Benefit of (the Funds) / the Counterparties 4,560,857  
ProShares Ultra Silver [Member] | Societe Generale S.A. [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition   2,761,817
Financial Instruments for the Benefit of (the Funds) / the Counterparties   (2,516,153)
Net Amounts of Assets presented in the Statements of Financial Condition   245,664
Amounts of Recognized Assets presented in the Statements of Financial Condition (1,789,967)  
Financial Instruments for the Benefit of (the Funds) / the Counterparties 1,789,967  
ProShares VIX Short-Term Futures ETF [Member] | Goldman Sachs International [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition (1,038,439)  
Cash Collateral for the Benefit of (the Funds) / the Counterparties 1,038,439  
ProShares VIX Short-Term Futures ETF [Member] | Deutsche Bank [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 1,302,919  
Cash Collateral for the Benefit of (the Funds) / the Counterparties (1,302,919)  
ProShares Ultra Yen [Member] | Goldman Sachs International [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition (11,885) (17,410)
Financial Instruments for the Benefit of (the Funds) / the Counterparties   17,410
Cash Collateral for the Benefit of (the Funds) / the Counterparties 11,885  
Net Amounts of Liabilities presented in the Statements of Financial Condition  
ProShares Ultra Yen [Member] | UBS AG [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition (12,374) (17,414)
Financial Instruments for the Benefit of (the Funds) / the Counterparties   17,414
Cash Collateral for the Benefit of (the Funds) / the Counterparties 12,374  
Net Amounts of Liabilities presented in the Statements of Financial Condition  
ProShares UltraShort Bloomberg Crude Oil [Member] | Goldman Sachs International [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition (8,713,478) (9,242,398)
Financial Instruments for the Benefit of (the Funds) / the Counterparties 8,713,478 9,242,398
Net Amounts of Liabilities presented in the Statements of Financial Condition  
ProShares UltraShort Bloomberg Crude Oil [Member] | UBS AG [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition (8,567,454) (9,287,467)
Financial Instruments for the Benefit of (the Funds) / the Counterparties 6,870,954 9,287,467
Cash Collateral for the Benefit of (the Funds) / the Counterparties 1,696,500  
Net Amounts of Liabilities presented in the Statements of Financial Condition  
ProShares UltraShort Bloomberg Crude Oil [Member] | Citibank N.A. [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition (11,914,957) (10,173,164)
Financial Instruments for the Benefit of (the Funds) / the Counterparties 11,914,957 10,173,164
Net Amounts of Liabilities presented in the Statements of Financial Condition  
ProShares UltraShort Bloomberg Crude Oil [Member] | Societe Generale S.A. [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition (3,627,720) (1,904,113)
Financial Instruments for the Benefit of (the Funds) / the Counterparties 3,627,720 1,904,113
Net Amounts of Liabilities presented in the Statements of Financial Condition  
ProShares UltraShort Bloomberg Crude Oil [Member] | RBC. NA [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition (944,591)  
Net Amounts of Liabilities presented in the Statements of Financial Condition (944,591)  
ProShares UltraShort Euro [Member] | Goldman Sachs International [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 1,779,254  
Financial Instruments for the Benefit of (the Funds) / the Counterparties (1,779,254)  
Amounts of Recognized Assets presented in the Statements of Financial Condition   (3,297,612)
Financial Instruments for the Benefit of (the Funds) / the Counterparties   259,612
Cash Collateral for the Benefit of (the Funds) / the Counterparties   3,038,000
Net Amounts of Liabilities presented in the Statements of Financial Condition  
ProShares UltraShort Euro [Member] | UBS AG [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 1,620,696  
Financial Instruments for the Benefit of (the Funds) / the Counterparties (1,620,696)  
Amounts of Recognized Assets presented in the Statements of Financial Condition   (3,046,657)
Financial Instruments for the Benefit of (the Funds) / the Counterparties   3,046,657
Net Amounts of Liabilities presented in the Statements of Financial Condition  
ProShares UltraShort Gold [Member] | Goldman Sachs International [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 615,252  
Financial Instruments for the Benefit of (the Funds) / the Counterparties (577,828)  
Net Amounts of Assets presented in the Statements of Financial Condition 37,424  
Amounts of Recognized Assets presented in the Statements of Financial Condition   (428,358)
Financial Instruments for the Benefit of (the Funds) / the Counterparties   428,358
Net Amounts of Liabilities presented in the Statements of Financial Condition  
ProShares UltraShort Gold [Member] | UBS AG [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 621,773  
Financial Instruments for the Benefit of (the Funds) / the Counterparties (581,161)  
Net Amounts of Assets presented in the Statements of Financial Condition 40,612  
Amounts of Recognized Assets presented in the Statements of Financial Condition   (378,414)
Financial Instruments for the Benefit of (the Funds) / the Counterparties   378,414
Net Amounts of Liabilities presented in the Statements of Financial Condition  
ProShares UltraShort Gold [Member] | Citibank N.A. [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 793,507  
Net Amounts of Assets presented in the Statements of Financial Condition 793,507  
Amounts of Recognized Assets presented in the Statements of Financial Condition   (554,559)
Financial Instruments for the Benefit of (the Funds) / the Counterparties   554,559
Net Amounts of Liabilities presented in the Statements of Financial Condition  
ProShares UltraShort Gold [Member] | Societe Generale S.A. [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 246,078  
Financial Instruments for the Benefit of (the Funds) / the Counterparties (246,078)  
Amounts of Recognized Assets presented in the Statements of Financial Condition   (126,928)
Financial Instruments for the Benefit of (the Funds) / the Counterparties   126,928
Net Amounts of Liabilities presented in the Statements of Financial Condition  
ProShares UltraShort Silver [Member] | Goldman Sachs International [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 402,097  
Financial Instruments for the Benefit of (the Funds) / the Counterparties (349,222)  
Net Amounts of Assets presented in the Statements of Financial Condition 52,875  
Amounts of Recognized Assets presented in the Statements of Financial Condition   (486,240)
Cash Collateral for the Benefit of (the Funds) / the Counterparties   486,240
Net Amounts of Liabilities presented in the Statements of Financial Condition  
ProShares UltraShort Silver [Member] | UBS AG [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 384,979  
Net Amounts of Assets presented in the Statements of Financial Condition 384,979  
Amounts of Recognized Assets presented in the Statements of Financial Condition   (482,025)
Financial Instruments for the Benefit of (the Funds) / the Counterparties   482,025
Net Amounts of Liabilities presented in the Statements of Financial Condition  
ProShares UltraShort Silver [Member] | Citibank N.A. [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 582,164  
Net Amounts of Assets presented in the Statements of Financial Condition 582,164  
Amounts of Recognized Assets presented in the Statements of Financial Condition   (632,593)
Financial Instruments for the Benefit of (the Funds) / the Counterparties   632,593
Net Amounts of Liabilities presented in the Statements of Financial Condition  
ProShares UltraShort Silver [Member] | Societe Generale S.A. [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 83,545  
Net Amounts of Assets presented in the Statements of Financial Condition 83,545  
Amounts of Recognized Assets presented in the Statements of Financial Condition   (115,305)
Financial Instruments for the Benefit of (the Funds) / the Counterparties   115,305
Net Amounts of Liabilities presented in the Statements of Financial Condition  
ProShares UltraShort Yen [Member] | Goldman Sachs International [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 348,163 821,317
Financial Instruments for the Benefit of (the Funds) / the Counterparties   (810,030)
Net Amounts of Assets presented in the Statements of Financial Condition 348,163 11,287
ProShares UltraShort Yen [Member] | UBS AG [Member]    
Derivative [Line Items]    
Amounts of Recognized Assets presented in the Statements of Financial Condition 345,155 705,946
Cash Collateral for the Benefit of (the Funds) / the Counterparties   $ (705,946)
Net Amounts of Assets presented in the Statements of Financial Condition $ 345,155