v2.4.0.6

Investments (Financial Liabilities, Derivative Liabilities, And Collateral Pledged By Counterparty) (Detail) (USD $) | Mar. 31, 2013 | Dec. 31, 2012
--- | --- | ---
ProShares UltraShort DJ-UBS Commodity [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | $ 92,919 |
Financial Instruments | (92,919) |
ProShares UltraShort DJ-UBS Commodity [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 64,434 |
Financial Instruments | (64,434) |
ProShares UltraShort DJ-UBS Commodity [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 28,485 |
Financial Instruments | (28,485) |
ProShares UltraShort DJ-UBS Crude Oil [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 12,719,387 | 6,586,396
Financial Instruments | (11,368,414) | (5,607,060)
Cash Collateral Pledged | (1,350,973) | (979,336)
ProShares UltraShort DJ-UBS Crude Oil [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 6,252,210 | 1,880,292
Financial Instruments | (6,252,210) | (1,880,292)
ProShares UltraShort DJ-UBS Crude Oil [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 3,986,152 | 1,996,402
Financial Instruments | (3,986,152) | (1,996,402)
ProShares UltraShort DJ-UBS Crude Oil [Member] | Goldman Sachs & Co.Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 1,350,973 | 979,336
Cash Collateral Pledged | (1,350,973) | (979,336)
ProShares UltraShort DJ-UBS Crude Oil [Member] | Societe Generale S.A. [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 1,130,052 | 1,730,366
Financial Instruments | (1,130,052) | (1,730,366)
ProShares UltraShort DJ-UBS Natural Gas [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  |
Financial Instruments |  |
Cash Collateral Pledged |  |
Net Amount |  |
ProShares UltraShort Gold [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 3,246,282 | 3,980
Financial Instruments | (3,246,282) |
Cash Collateral Pledged |  | (3,980)
ProShares UltraShort Gold [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 589,404 |
Financial Instruments | (589,404) |
ProShares UltraShort Gold [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 444,201 |
Financial Instruments | (444,201) |
ProShares UltraShort Gold [Member] | Goldman Sachs & Co.Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  | 3,980
Cash Collateral Pledged |  | (3,980)
ProShares UltraShort Gold [Member] | Societe Generale S.A. [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 460,599 |
Financial Instruments | (460,599) |
ProShares UltraShort Gold [Member] | Deutsche Bank AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 1,752,078 |
Financial Instruments | (1,752,078) |
ProShares UltraShort Silver [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 11,313 | 2,520
Financial Instruments | (11,313) |
Cash Collateral Pledged |  | (2,520)
ProShares UltraShort Silver [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 11,313 |
Financial Instruments | (11,313) |
ProShares UltraShort Silver [Member] | Goldman Sachs & Co.Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  | 2,520
Cash Collateral Pledged |  | (2,520)
ProShares Short Euro [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 12,300 |
Cash Collateral Pledged | (12,300) |
ProShares Short Euro [Member] | RBC Capital Markets [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 12,300 |
Cash Collateral Pledged | (12,300) |
ProShares UltraShort Australian Dollar [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  | 10,950
Financial Instruments |  |
Cash Collateral Pledged |  | (10,950)
Net Amount |  |
ProShares UltraShort Australian Dollar [Member] | RBC Capital Markets [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  | 10,950
Cash Collateral Pledged |  | (10,950)
ProShares UltraShort Euro [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 1,439,211 | 13,398,619
Financial Instruments | (1,439,211) | (13,398,619)
ProShares UltraShort Euro [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 930,513 | 6,048,832
Financial Instruments | (930,513) | (6,048,832)
ProShares UltraShort Euro [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 508,698 | 7,349,787
Financial Instruments | (508,698) | (7,349,787)
ProShares UltraShort Yen [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  | 232,642
Financial Instruments |  | (232,642)
Cash Collateral Pledged |  |
Net Amount |  |
ProShares UltraShort Yen [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  | 232,642
Financial Instruments |  | (232,642)
ProShares Ultra DJ-UBS Commodity [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  | 306,268
Financial Instruments |  | (306,268)
Cash Collateral Pledged |  |
Net Amount |  |
ProShares Ultra DJ-UBS Commodity [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  | 198,117
Financial Instruments |  | (198,117)
ProShares Ultra DJ-UBS Commodity [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  | 108,151
Financial Instruments |  | (108,151)
ProShares Ultra DJ-UBS Crude Oil [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  |
Financial Instruments |  |
Cash Collateral Pledged |  |
Net Amount |  |
ProShares Ultra DJ-UBS Natural Gas [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 834,689 | 4,891,783
Cash Collateral Pledged | (834,689) | (4,891,783)
ProShares Ultra DJ-UBS Natural Gas [Member] | Goldman Sachs & Co.Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 834,689 | 4,891,783
Cash Collateral Pledged | (834,689) | (4,891,783)
ProShares Ultra Gold [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 2,300 | 15,652,058
Financial Instruments |  | (15,652,058)
Cash Collateral Pledged | (2,300) |
ProShares Ultra Gold [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  | 3,678,367
Financial Instruments |  | (3,678,367)
ProShares Ultra Gold [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  | 3,634,829
Financial Instruments |  | (3,634,829)
ProShares Ultra Gold [Member] | Goldman Sachs & Co.Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 2,300 |
Cash Collateral Pledged | (2,300) |
ProShares Ultra Gold [Member] | Societe Generale S.A. [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  | 3,715,989
Financial Instruments |  | (3,715,989)
ProShares Ultra Gold [Member] | Deutsche Bank AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  | 4,622,873
Financial Instruments |  | (4,622,873)
ProShares Ultra Silver [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 8,109,608 | 145,740,706
Financial Instruments | (8,106,718) | (143,623,808)
Cash Collateral Pledged | (2,890) |
Net Amount |  | 2,116,898
ProShares Ultra Silver [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 1,237,902 | 34,491,042
Financial Instruments | (1,237,902) | (34,491,042)
ProShares Ultra Silver [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 1,005,386 | 31,574,331
Financial Instruments | (1,005,386) | (31,574,331)
ProShares Ultra Silver [Member] | Goldman Sachs & Co.Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 2,890 |
Cash Collateral Pledged | (2,890) |
ProShares Ultra Silver [Member] | Societe Generale S.A. [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 1,056,353 | 34,802,217
Financial Instruments | (1,056,353) | (34,802,217)
ProShares Ultra Silver [Member] | Deutsche Bank AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 4,807,077 | 44,873,116
Financial Instruments | (4,807,077) | (42,756,218)
Net Amount |  | 2,116,898
ProShares Ultra Australian Dollar [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 22,982 |
Cash Collateral Pledged | (22,982) |
ProShares Ultra Australian Dollar [Member] | RBC Capital Markets [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 22,982 |
Cash Collateral Pledged | (22,982) |
ProShares Ultra Euro [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 137,134 | 2,314
Financial Instruments | (137,134) | (2,314)
ProShares Ultra Euro [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 63,478 | 635
Financial Instruments | (63,478) | (635)
ProShares Ultra Euro [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 73,656 | 1,679
Financial Instruments | (73,656) | (1,679)
ProShares Ultra Yen [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 70,562 | 507,819
Financial Instruments | (70,562) | (410,046)
Net Amount |  | 97,773
ProShares Ultra Yen [Member] | Goldman Sachs International (Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 22,860 | 231,047
Financial Instruments | (22,860) | (231,047)
ProShares Ultra Yen [Member] | UBS AG [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 47,702 | 276,772
Financial Instruments | (47,702) | (178,999)
Net Amount |  | 97,773
ProShares VIX Short-Term Futures ETF [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 2,471,348 | 31,540,181
Cash Collateral Pledged | (2,471,348) | (31,540,181)
ProShares VIX Short-Term Futures ETF [Member] | RBC Capital Markets [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 2,471,348 | 31,540,181
Cash Collateral Pledged | (2,471,348) | (31,540,181)
ProShares VIX Mid-Term Futures ETF [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  | 1,890,675
Financial Instruments |  |
Cash Collateral Pledged |  | (1,890,675)
Net Amount |  |
ProShares VIX Mid-Term Futures ETF [Member] | RBC Capital Markets [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  | 1,890,675
Cash Collateral Pledged |  | (1,890,675)
ProShares Ultra VIX Short-Term Futures ETF [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 4,961,933 | 35,666,735
Cash Collateral Pledged | (4,961,933) | (35,666,735)
ProShares Ultra VIX Short-Term Futures ETF [Member] | RBC Capital Markets [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition | 4,961,933 | 35,666,735
Cash Collateral Pledged | (4,961,933) | (35,666,735)
ProShares Short VIX Short-Term Futures ETF [Member] |  |
Derivative [Line Items] |  |
Net Amounts of Liabilities Presented in the Statement of Financial Condition |  |
Financial Instruments |  |
Cash Collateral Pledged |  |
Net Amount |  |

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