v2.4.0.6

Significant Accounting Policies (Valuation of Investments) (Detail) (USD $) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2013 | Dec. 31, 2012
Significant Accounting Policies [Line Items] |  |
Level III portfolio investments | $ 0 | $ 0
ProShares UltraShort DJ-UBS Commodity [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 2,969,893 | 2,952,406
ProShares UltraShort DJ-UBS Crude Oil [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 134,336,722 | 77,409,608
ProShares UltraShort DJ-UBS Natural Gas [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 17,696,463 | 10,451,866
ProShares UltraShort Gold [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 104,909,385 | 92,320,494
ProShares UltraShort Silver [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 105,630,051 | 105,554,406
ProShares Short Euro [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,433,678 | 3,354,848
ProShares UltraShort Australian Dollar [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,220,400 | 3,388,497
ProShares UltraShort Euro [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 520,855,991 | 540,282,990
ProShares UltraShort Yen [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 466,350,321 | 400,857,406
ProShares Ultra DJ-UBS Commodity [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,465,699 | 5,934,683
ProShares Ultra DJ-UBS Crude Oil [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 330,556,198 | 492,956,680
ProShares Ultra DJ-UBS Natural Gas [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 67,746,797 | 60,496,274
ProShares Ultra Gold [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 316,607,862 | 334,957,606
ProShares Ultra Silver [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 746,826,870 | 745,276,660
ProShares Ultra Australian Dollar [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,801,832 | 3,471,864
ProShares Ultra Euro [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 4,344,924 | 4,634,103
ProShares Ultra Yen [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,464,372 | 4,093,622
ProShares VIX Short-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 144,590,749 | 143,839,502
ProShares VIX Mid-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 47,826,009 | 78,460,456
ProShares Ultra VIX Short-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 100,047,635 | 99,799,256
ProShares Short VIX Short-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 48,219,559 | 52,299,177
Total Trust [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,176,901,410 | 3,262,792,404
Level I - Quoted Prices [Member] | ProShares UltraShort DJ-UBS Commodity [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,062,812 | 2,803,904
Level I - Quoted Prices [Member] | ProShares UltraShort DJ-UBS Crude Oil [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 145,473,612 | 87,046,389
Level I - Quoted Prices [Member] | ProShares UltraShort DJ-UBS Crude Oil [Member] | VIX Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 231,524 | (4,029,721)
Level I - Quoted Prices [Member] | ProShares UltraShort DJ-UBS Natural Gas [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 21,193,216 | 10,042,731
Level I - Quoted Prices [Member] | ProShares UltraShort DJ-UBS Natural Gas [Member] | VIX Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (3,496,753) | 409,135
Level I - Quoted Prices [Member] | ProShares UltraShort Gold [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 108,157,077 | 88,575,398
Level I - Quoted Prices [Member] | ProShares UltraShort Gold [Member] | VIX Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (1,410) | 15,240
Level I - Quoted Prices [Member] | ProShares UltraShort Silver [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 105,347,243 | 86,206,701
Level I - Quoted Prices [Member] | ProShares UltraShort Silver [Member] | VIX Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 27,520 | 40,020
Level I - Quoted Prices [Member] | ProShares Short Euro [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,371,965 | 3,409,904
Level I - Quoted Prices [Member] | ProShares Short Euro [Member] | VIX Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 61,713 | (55,056)
Level I - Quoted Prices [Member] | ProShares UltraShort Australian Dollar [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,329,970 | 3,302,907
Level I - Quoted Prices [Member] | ProShares UltraShort Australian Dollar [Member] | VIX Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (109,570) | 85,590
Level I - Quoted Prices [Member] | ProShares UltraShort Euro [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 507,190,542 | 553,430,562
Level I - Quoted Prices [Member] | ProShares UltraShort Yen [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 463,617,695 | 362,743,231
Level I - Quoted Prices [Member] | ProShares Ultra DJ-UBS Commodity [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,350,652 | 6,240,951
Level I - Quoted Prices [Member] | ProShares Ultra DJ-UBS Crude Oil [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 304,000,111 | 437,662,650
Level I - Quoted Prices [Member] | ProShares Ultra DJ-UBS Crude Oil [Member] | VIX Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 1,362,516 | 21,960,410
Level I - Quoted Prices [Member] | ProShares Ultra DJ-UBS Natural Gas [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 53,702,179 | 64,313,224
Level I - Quoted Prices [Member] | ProShares Ultra DJ-UBS Natural Gas [Member] | VIX Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 14,044,618 | (3,816,950)
Level I - Quoted Prices [Member] | ProShares Ultra Gold [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 307,384,042 | 350,624,904
Level I - Quoted Prices [Member] | ProShares Ultra Gold [Member] | VIX Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 1,380 | (15,240)
Level I - Quoted Prices [Member] | ProShares Ultra Silver [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 754,961,358 | 891,057,386
Level I - Quoted Prices [Member] | ProShares Ultra Silver [Member] | VIX Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (27,770) | (40,020)
Level I - Quoted Prices [Member] | ProShares Ultra Australian Dollar [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,676,902 | 3,570,894
Level I - Quoted Prices [Member] | ProShares Ultra Australian Dollar [Member] | VIX Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 124,930 | (99,030)
Level I - Quoted Prices [Member] | ProShares Ultra Euro [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 4,478,920 | 4,546,944
Level I - Quoted Prices [Member] | ProShares Ultra Yen [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,534,934 | 4,587,918
Level I - Quoted Prices [Member] | ProShares VIX Short-Term Futures ETF [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 152,936,809 | 144,060,921
Level I - Quoted Prices [Member] | ProShares VIX Short-Term Futures ETF [Member] | VIX Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (8,346,060) | (221,419)
Level I - Quoted Prices [Member] | ProShares VIX Mid-Term Futures ETF [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 49,702,438 | 79,930,866
Level I - Quoted Prices [Member] | ProShares VIX Mid-Term Futures ETF [Member] | VIX Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (1,876,429) | (1,470,410)
Level I - Quoted Prices [Member] | ProShares Ultra VIX Short-Term Futures ETF [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 118,784,756 | 97,440,843
Level I - Quoted Prices [Member] | ProShares Ultra VIX Short-Term Futures ETF [Member] | VIX Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (18,737,121) | 2,057,062
Level I - Quoted Prices [Member] | ProShares Short VIX Short-Term Futures ETF [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 45,830,843 | 53,686,352
Level I - Quoted Prices [Member] | ProShares Short VIX Short-Term Futures ETF [Member] | VIX Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 2,388,716 | (1,387,175)
Level I - Quoted Prices [Member] | Total Trust [Member] | Short-Term U.S. Government And Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,163,088,076 | 3,335,285,580
Level I - Quoted Prices [Member] | Total Trust [Member] | VIX Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (14,352,196) | 13,432,436
Level II - Other Significant Observable Inputs [Member] | ProShares UltraShort DJ-UBS Commodity [Member] | Swap Agreements [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (92,919) | 148,502
Level II - Other Significant Observable Inputs [Member] | ProShares UltraShort DJ-UBS Crude Oil [Member] | Swap Agreements [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (11,368,414) | (5,607,060)
Level II - Other Significant Observable Inputs [Member] | ProShares UltraShort Gold [Member] | Swap agreements or forward contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (3,246,282) | 3,729,856
Level II - Other Significant Observable Inputs [Member] | ProShares UltraShort Silver [Member] | Swap agreements or forward contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 255,288 | 19,307,685
Level II - Other Significant Observable Inputs [Member] | ProShares UltraShort Euro [Member] | Foreign Currency Forward Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 13,665,449 | (13,147,572)
Level II - Other Significant Observable Inputs [Member] | ProShares UltraShort Yen [Member] | Foreign Currency Forward Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 2,732,626 | 38,114,175
Level II - Other Significant Observable Inputs [Member] | ProShares Ultra DJ-UBS Commodity [Member] | Swap Agreements [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 115,047 | (306,268)
Level II - Other Significant Observable Inputs [Member] | ProShares Ultra DJ-UBS Crude Oil [Member] | Swap Agreements [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 25,193,571 | 33,333,620
Level II - Other Significant Observable Inputs [Member] | ProShares Ultra Gold [Member] | Swap agreements or forward contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 9,222,440 | (15,652,058)
Level II - Other Significant Observable Inputs [Member] | ProShares Ultra Silver [Member] | Swap agreements or forward contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (8,106,718) | (145,740,706)
Level II - Other Significant Observable Inputs [Member] | ProShares Ultra Euro [Member] | Foreign Currency Forward Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (133,996) | 87,159
Level II - Other Significant Observable Inputs [Member] | ProShares Ultra Yen [Member] | Foreign Currency Forward Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (70,562) | (494,296)
Level II - Other Significant Observable Inputs [Member] | ProShares Ultra VIX Short-Term Futures ETF [Member] | Swap Agreements [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure |  | 301,351
Level II - Other Significant Observable Inputs [Member] | Total Trust [Member] | Swap agreements or forward contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (1,875,272) | (138,355,223)
Level II - Other Significant Observable Inputs [Member] | Total Trust [Member] | Foreign Currency Forward Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 16,193,517 | 24,559,466
Level II - Other Significant Observable Inputs [Member] | Total Trust [Member] | Swap Agreements [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | $ 13,847,285 | $ 27,870,145

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- Definition Level Three Portfolio Investments For Significant Unobservable Inputs Fair Value + References No definition available. + Details
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- Definition This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents investment securities as of the balance sheet date which may include marketable securities, derivative financial instruments, and investments accounted for under the equity method. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Trading Securities -URI http://asc.fasb.org/extlink&oid=6526789 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=7534914&loc=d3e22054-111558 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 13 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Subparagraph a, f, g -Article 7 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Available-for-Sale Securities -URI http://asc.fasb.org/extlink&oid=6505594 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 12 -Subparagraph a -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 35 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=16383099&loc=d3e24584-111560 + Details
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