v2.4.0.6
Schedule of Investments (Futures Contracts Sold) (Detail) (USD $)
Mar. 31, 2013
ProShares UltraShort DJ-UBS Crude Oil [Member]
  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) $ (11,368,414) [1]
ProShares UltraShort DJ-UBS Crude Oil [Member] | Crude Oil - NYMEX, expires May 2013 [Member]
  
Schedule of Investments [Line Items]  
Number of Contracts 1,528 [2]
Notional Amount at Value 148,567,440 [2]
Unrealized Appreciation (Depreciation) 231,524 [2]
ProShares UltraShort DJ-UBS Natural Gas [Member] | Natural Gas - NYMEX, expires May 2013 [Member]
  
Schedule of Investments [Line Items]  
Number of Contracts 1,250 [3]
Notional Amount at Value 50,300,000 [3]
Unrealized Appreciation (Depreciation) (3,496,753) [3]
ProShares UltraShort Gold [Member]
  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) (3,246,282) [1]
ProShares UltraShort Gold [Member] | Gold Futures - COMEX, Expires June 2013 [Member]
  
Schedule of Investments [Line Items]  
Number of Contracts 2 [4]
Notional Amount at Value 319,140 [4]
Unrealized Appreciation (Depreciation) (1,410) [4]
ProShares UltraShort Silver [Member]
  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) 255,288 [1]
ProShares UltraShort Silver [Member] | Silver Futures - COMEX, expires May 2013 [Member]
  
Schedule of Investments [Line Items]  
Number of Contracts 2 [5]
Notional Amount at Value 283,230 [5]
Unrealized Appreciation (Depreciation) 27,520 [5]
ProShares Short Euro [Member] | Euro Fx Currency Futures - CME, expires June 2013 [Member]
  
Schedule of Investments [Line Items]  
Number of Contracts 24 [6]
Notional Amount at Value 3,846,900 [6]
Unrealized Appreciation (Depreciation) 61,713 [6]
ProShares UltraShort Australian Dollar [Member] | Australian Dollar Fx Currency Futures - CME, expires June 2013 [Member]
  
Schedule of Investments [Line Items]  
Number of Contracts 71 [7]
Notional Amount at Value 7,350,630 [7]
Unrealized Appreciation (Depreciation) (109,570) [7]
ProShares Short VIX Short-Term Futures ETF [Member]
  
Schedule of Investments [Line Items]  
Unrealized Appreciation (Depreciation) 2,388,716 [8]
ProShares Short VIX Short-Term Futures ETF [Member] | VIX Futures - CBOE, expires April 2013 [Member]
  
Schedule of Investments [Line Items]  
Number of Contracts 2,965 [8]
Notional Amount at Value 42,103,000 [8]
Unrealized Appreciation (Depreciation) 2,122,730 [8]
ProShares Short VIX Short-Term Futures ETF [Member] | VIX Futures - CBOE, expires May 2013 [Member]
  
Schedule of Investments [Line Items]  
Number of Contracts 1,718 [8]
Notional Amount at Value 26,800,800 [8]
Unrealized Appreciation (Depreciation) $ 265,986 [8]
[1] The positions and counterparties herein are as of March 31, 2013. The Funds continually evaluate different counterparties for their transactions and counterparties are subject to change. New counterparties can be added at any time.
[2] Cash collateral in the amount of $7,563,600 was pledged to cover margin requirements for open futures contracts as of March 31, 2013.
[3] Cash collateral in the amount of $2,887,500 was pledged to cover margin requirements for open futures contracts as of March 31, 2013.
[4] Cash collateral in the amount of $11,880 was pledged to cover margin requirements for open futures contracts as of March 31, 2013.
[5] Cash collateral in the amount of $20,900 was pledged to cover margin requirements for open futures contracts as of March 31, 2013.
[6] Cash collateral in the amount of $59,400 was pledged to cover margin requirements for open futures contracts as of March 31, 2013.
[7] Cash collateral in the amount of $117,150 was pledged to cover margin requirements for open futures contracts as of March 31, 2013.
[8] Cash collateral in the amount of $21,073,502 was pledged to cover margin requirements for open futures contracts as of March 31, 2013.