v3.10.0.1

Significant Accounting Policies - Valuation of Investments using Fair Value Hierarchy (Detail) - USD ($) | Jun. 30, 2018 | Dec. 31, 2017
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ProShares Short Euro [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | $ 5,774,277 | $ 6,829,947
ProShares Short VIX Short-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 70,467,597 | 511,952,093
ProShares Ultra Bloomberg Crude Oil [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 465,673,601 | 533,700,242
ProShares Ultra Bloomberg Natural Gas [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 17,841,803 | 58,187,166
ProShares Ultra Euro [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,116,986 | 7,260,387
ProShares Ultra Gold [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 80,679,374 | 92,536,679
ProShares Ultra Silver [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 198,352,203 | 257,318,650
ProShares Ultra VIX Short-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 83,060,057 | 253,067,012
ProShares Ultra Yen [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 973,825 | 1,963,109
Proshares Ultra Pro 3x Crude Oil ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 9,905,484 | 1,417,998
ProShares UltraPro 3X Short Crude Oil ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (5,442,454) | (2,988,155)
ProShares UltraShort Australian Dollar [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 5,380,099 | 11,090,684
ProShares UltraShort Bloomberg Crude Oil [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 132,722,064 | 219,077,033
ProShares UltraShort Bloomberg Natural Gas [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 4,099,474 | 2,902,702
ProShares UltraShort Euro [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 145,052,935 | 198,425,897
ProShares UltraShort Gold [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 25,246,424 | 30,484,181
ProShares UltraShort Silver [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 21,433,180 | 16,632,048
ProShares UltraShort Yen [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 81,530,454 | 133,361,615
ProShares VIX Mid-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (378,240) | 18,778,235
ProShares VIX Short-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 31,425,513 | 130,083,727
Total Trust [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 1,376,914,656 | 2,482,081,250
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 | 5,687,064 | 6,996,235
Level I - Quoted Prices [Member] | ProShares Short Euro [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 87,213 | (166,288)
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 | 92,995,995 | 494,910,644
Level I - Quoted Prices [Member] | ProShares Short VIX Short-Term Futures ETF [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (22,528,398) | 17,041,449
Level I - Quoted Prices [Member] | ProShares Ultra Bloomberg Crude Oil [Member] | Short-Term U.S. Government and Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 365,955,628 | 459,515,902
Level I - Quoted Prices [Member] | ProShares Ultra Bloomberg Crude Oil [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 17,289,103 | 11,945,979
Level I - Quoted Prices [Member] | ProShares Ultra Bloomberg Natural Gas [Member] | Short-Term U.S. Government and Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 17,960,426 | 50,961,356
Level I - Quoted Prices [Member] | ProShares Ultra Bloomberg Natural Gas [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (118,623) | 7,225,810
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 | 3,289,040 | 6,996,235
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 | 87,847,390 | 88,884,844
Level I - Quoted Prices [Member] | ProShares Ultra Gold [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (15,120) | 5,480
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 | 212,508,884 | 235,581,716
Level I - Quoted Prices [Member] | ProShares Ultra Silver [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (7,970) | 1,600
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 | 42,998,148 | 287,533,132
Level I - Quoted Prices [Member] | ProShares Ultra VIX Short-Term Futures ETF [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 39,797,429 | (34,466,120)
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 | 998,084 | 1,997,933
Level I - Quoted Prices [Member] | Proshares Ultra Pro 3x Crude Oil ETF [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 9,905,484 | 1,417,998
Level I - Quoted Prices [Member] | ProShares UltraPro 3X Short Crude Oil ETF [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (5,442,454) | (2,988,155)
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 | 4,988,329 | 11,983,904
Level I - Quoted Prices [Member] | ProShares UltraShort Australian Dollar [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 391,770 | (893,220)
Level I - Quoted Prices [Member] | ProShares UltraShort Bloomberg Crude Oil [Member] | Short-Term U.S. Government and Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 173,652,213 | 253,646,823
Level I - Quoted Prices [Member] | ProShares UltraShort Bloomberg Crude Oil [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (7,161,949) | (3,962,648)
Level I - Quoted Prices [Member] | ProShares UltraShort Bloomberg Natural Gas [Member] | Short-Term U.S. Government and Agencies [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 4,093,202 | 3,999,751
Level I - Quoted Prices [Member] | ProShares UltraShort Bloomberg Natural Gas [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 6,272 | (1,097,049)
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 | 141,652,985 | 204,770,166
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 | 22,954,734 | 31,977,900
Level I - Quoted Prices [Member] | ProShares UltraShort Gold [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 15,080 | (5,460)
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 | 19,972,425 | 18,349,861
Level I - Quoted Prices [Member] | ProShares UltraShort Silver [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 7,970 | (1,650)
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 | 80,837,136 | 131,834,352
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 |  | 20,993,515
Level I - Quoted Prices [Member] | ProShares VIX Mid-Term Futures ETF [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (378,240) | (2,215,280)
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 | 21,999,053 | 134,845,604
Level I - Quoted Prices [Member] | ProShares VIX Short-Term Futures ETF [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 9,426,460 | (4,761,877)
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 | 1,300,390,736 | 2,445,779,873
Level I - Quoted Prices [Member] | Total Trust [Member] | Futures Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 41,274,027 | (12,919,431)
Level II - Other Significant Observable Inputs [Member] | ProShares Ultra Bloomberg Crude Oil [Member] | Swap Agreements [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 82,428,870 | 62,238,361
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 | (172,054) | 264,152
Level II - Other Significant Observable Inputs [Member] | ProShares Ultra Gold [Member] | Forward Agreements [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (7,152,896) | 3,646,355
Level II - Other Significant Observable Inputs [Member] | ProShares Ultra Silver [Member] | Forward Agreements [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (14,148,711) | 21,735,334
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 | 264,480 |
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 | (24,259) | (34,824)
Level II - Other Significant Observable Inputs [Member] | ProShares UltraShort Bloomberg Crude Oil [Member] | Swap Agreements [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (33,768,200) | (30,607,142)
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 | 3,399,950 | (6,344,269)
Level II - Other Significant Observable Inputs [Member] | ProShares UltraShort Gold [Member] | Forward Agreements [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 2,276,610 | (1,488,259)
Level II - Other Significant Observable Inputs [Member] | ProShares UltraShort Silver [Member] | Forward Agreements [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 1,452,785 | (1,716,163)
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 | 693,318 | 1,527,263
Level II - Other Significant Observable Inputs [Member] | Total Trust [Member] | Forward Agreements [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (17,572,212) | 22,177,267
Level II - Other Significant Observable Inputs [Member] | Total Trust [Member] | Foreign Currency Forward Contracts [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,896,955 | (4,587,678)
Level II - Other Significant Observable Inputs [Member] | Total Trust [Member] | Swap Agreements [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | $ 48,925,150 | $ 31,631,219

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