v2.4.0.6

Investments (Financial Assets, Derivative Assets, And Collateral Held By Counterparty) (Detail) (USD $) | Mar. 31, 2013 | Dec. 31, 2012
--- | --- | ---
ProShares UltraShort DJ-UBS Commodity [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | $ 148,502
Financial Instruments |  |
Cash Collateral Received |  |
Net Amount |  | 148,502
ProShares UltraShort DJ-UBS Commodity [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 104,181
Net Amount |  | 104,181
ProShares UltraShort DJ-UBS Commodity [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 44,321
Net Amount |  | 44,321
ProShares UltraShort DJ-UBS Crude Oil [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  |
Financial Instruments |  |
Cash Collateral Received |  |
Net Amount |  |
ProShares UltraShort DJ-UBS Natural Gas [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 442,358 | 632,777
Net Amount | 442,358 | 632,777
ProShares UltraShort DJ-UBS Natural Gas [Member] | Goldman Sachs & Co.Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 442,358 | 632,777
Net Amount | 442,358 | 632,777
ProShares UltraShort Gold [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 2,300 | 3,729,856
Net Amount | 2,300 | 3,729,856
ProShares UltraShort Gold [Member] | Goldman Sachs & Co.Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 2,300 |
Net Amount | 2,300 |
ProShares UltraShort Gold [Member] | Deutsche Bank AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 2,389,236
Net Amount |  | 2,389,236
ProShares UltraShort Gold [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 452,059
Net Amount |  | 452,059
ProShares UltraShort Gold [Member] | Societe Generale S.A. [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 499,264
Net Amount |  | 499,264
ProShares UltraShort Gold [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 389,297
Net Amount |  | 389,297
ProShares UltraShort Silver [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 269,491 | 19,307,685
Net Amount | 269,491 | 19,307,685
ProShares UltraShort Silver [Member] | Goldman Sachs & Co.Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 2,890 |
Net Amount | 2,890 |
ProShares UltraShort Silver [Member] | Deutsche Bank AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 55,643 | 10,786,801
Net Amount | 55,643 | 10,786,801
ProShares UltraShort Silver [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 63,340 | 3,141,119
Net Amount | 63,340 | 3,141,119
ProShares UltraShort Silver [Member] | Societe Generale S.A. [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 147,618 | 3,255,649
Net Amount | 147,618 | 3,255,649
ProShares UltraShort Silver [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 2,124,116
Net Amount |  | 2,124,116
ProShares Short Euro [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 6,612
Financial Instruments |  |
Cash Collateral Received |  |
Net Amount |  | 6,612
ProShares Short Euro [Member] | RBC Capital Markets [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 6,612
Net Amount |  | 6,612
ProShares UltraShort Australian Dollar [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 21,300 |
Net Amount | 21,300 |
ProShares UltraShort Australian Dollar [Member] | RBC Capital Markets [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 21,300 |
Net Amount | 21,300 |
ProShares UltraShort Euro [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 15,104,660 | 251,047
Net Amount | 15,104,660 | 251,047
ProShares UltraShort Euro [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 7,182,101 | 251,047
Net Amount | 7,182,101 | 251,047
ProShares UltraShort Euro [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 7,922,559 |
Net Amount | 7,922,559 |
ProShares UltraShort Yen [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 2,732,626 | 38,346,817
Net Amount | 2,732,626 | 38,346,817
ProShares UltraShort Yen [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 1,222,105 | 18,518,532
Net Amount | 1,222,105 | 18,518,532
ProShares UltraShort Yen [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 1,510,521 | 19,828,285
Net Amount | 1,510,521 | 19,828,285
ProShares Ultra DJ-UBS Commodity [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 115,047 |
Net Amount | 115,047 |
ProShares Ultra DJ-UBS Commodity [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 63,644 |
Net Amount | 63,644 |
ProShares Ultra DJ-UBS Commodity [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 51,403 |
Net Amount | 51,403 |
ProShares Ultra DJ-UBS Crude Oil [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 27,579,874 | 36,764,035
Net Amount | 27,579,874 | 36,764,035
ProShares Ultra DJ-UBS Crude Oil [Member] | Goldman Sachs & Co.Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 2,386,303 | 3,430,415
Net Amount | 2,386,303 | 3,430,415
ProShares Ultra DJ-UBS Crude Oil [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 8,318,017 | 14,334,730
Net Amount | 8,318,017 | 14,334,730
ProShares Ultra DJ-UBS Crude Oil [Member] | Societe Generale S.A. [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 4,601,585 | 8,989,866
Net Amount | 4,601,585 | 8,989,866
ProShares Ultra DJ-UBS Crude Oil [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 12,273,969 | 10,009,024
Net Amount | 12,273,969 | 10,009,024
ProShares Ultra DJ-UBS Natural Gas [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  |
Financial Instruments |  |
Cash Collateral Received |  |
Net Amount |  |
ProShares Ultra Gold [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 9,222,440 | 3,980
Net Amount | 9,222,440 | 3,980
ProShares Ultra Gold [Member] | Goldman Sachs & Co.Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 3,980
Net Amount |  | 3,980
ProShares Ultra Gold [Member] | Deutsche Bank AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 4,465,287 |
Net Amount | 4,465,287 |
ProShares Ultra Gold [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 1,574,862 |
Net Amount | 1,574,862 |
ProShares Ultra Gold [Member] | Societe Generale S.A. [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 1,671,035 |
Net Amount | 1,671,035 |
ProShares Ultra Gold [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 1,511,256 |
Net Amount | 1,511,256 |
ProShares Ultra Silver [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 2,520
Financial Instruments |  |
Cash Collateral Received |  |
Net Amount |  | 2,520
ProShares Ultra Silver [Member] | Goldman Sachs & Co.Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 2,520
Net Amount |  | 2,520
ProShares Ultra Australian Dollar [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 12,000
Financial Instruments |  |
Cash Collateral Received |  |
Net Amount |  | 12,000
ProShares Ultra Australian Dollar [Member] | RBC Capital Markets [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 12,000
Net Amount |  | 12,000
ProShares Ultra Euro [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 3,138 | 89,473
Net Amount | 3,138 | 89,473
ProShares Ultra Euro [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 737 | 38,327
Net Amount | 737 | 38,327
ProShares Ultra Euro [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 2,401 | 51,146
Net Amount | 2,401 | 51,146
ProShares Ultra Yen [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 13,523
Financial Instruments |  |
Cash Collateral Received |  |
Net Amount |  | 13,523
ProShares Ultra Yen [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 7,325
Net Amount |  | 7,325
ProShares Ultra Yen [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 6,198
Net Amount |  | 6,198
ProShares VIX Short-Term Futures ETF [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  |
Financial Instruments |  |
Cash Collateral Received |  |
Net Amount |  |
ProShares VIX Mid-Term Futures ETF [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 211,350 |
Net Amount | 211,350 |
ProShares VIX Mid-Term Futures ETF [Member] | RBC Capital Markets [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 211,350 |
Net Amount | 211,350 |
ProShares Ultra VIX Short-Term Futures ETF [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 301,351
Financial Instruments |  |
Cash Collateral Received |  |
Net Amount |  | 301,351
ProShares Ultra VIX Short-Term Futures ETF [Member] | Societe Generale S.A. [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition |  | 301,351
Net Amount |  | 301,351
ProShares Short VIX Short-Term Futures ETF [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 472,022 | 5,524,721
Net Amount | 472,022 | 5,524,721
ProShares Short VIX Short-Term Futures ETF [Member] | RBC Capital Markets [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Assets Presented in the Statement of Financial Condition | 472,022 | 5,524,721
Net Amount | $ 472,022 | $ 5,524,721

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