v2.4.0.8
Significant Accounting Policies - Calculation of Funds' Final Net Asset Value for Creation and Redemption of Fund Shares (Detail)
 6 Months Ended
Jun. 30, 2014
ProShares UltraShort Silver [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 7:00 a.m.
NAV Calculation Date June 30
ProShares Ultra Silver [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 7:00 a.m.
NAV Calculation Date June 30
ProShares UltraShort Gold [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 10:00 a.m.
NAV Calculation Date June 30
ProShares Ultra Gold [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 10:00 a.m.
NAV Calculation Date June 30
ProShares UltraShort Bloomberg Crude Oil [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 2:30 p.m.
NAV Calculation Date June 30
ProShares Ultra Bloomberg Crude Oil [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 2:30 p.m.
NAV Calculation Date June 30
ProShares UltraShort Bloomberg Natural Gas [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 2:30 p.m.
NAV Calculation Date June 30
ProShares Ultra Bloomberg Natural Gas [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 2:30 p.m.
NAV Calculation Date June 30
ProShares UltraShort Bloomberg Commodity [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 3:00 p.m.
NAV Calculation Date June 30
ProShares Ultra Bloomberg Commodity [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 3:00 p.m.
NAV Calculation Date June 30
ProShares UltraShort Australian Dollar [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 4:00 p.m.
NAV Calculation Date June 30
ProShares Ultra Australian Dollar [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 4:00 p.m.
NAV Calculation Date June 30
ProShares Short Euro [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 4:00 p.m.
NAV Calculation Date June 30
ProShares UltraShort Euro [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 4:00 p.m.
NAV Calculation Date June 30
ProShares Ultra Euro [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 4:00 p.m.
NAV Calculation Date June 30
ProShares UltraShort Yen [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 4:00 p.m.
NAV Calculation Date June 30
ProShares Ultra Yen [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 4:00 p.m.
NAV Calculation Date June 30
ProShares VIX Short-Term Futures ETF [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 4:15 p.m.
NAV Calculation Date June 30
ProShares Ultra VIX Short-Term Futures ETF [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 4:15 p.m.
NAV Calculation Date June 30
ProShares Short VIX Short-Term Futures ETF [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 4:15 p.m.
NAV Calculation Date June 30
ProShares VIX Mid-Term Futures ETF [Member]
  
Significant Accounting Policies [Line Items]  
NAV Calculation Time 4:15 p.m.
NAV Calculation Date June 30