v3.8.0.1

Significant Accounting Policies - Valuation of Investments using Fair Value Hierarchy (Detail) - USD ($) | Sep. 30, 2017 | Dec. 31, 2016
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ProShares VIX Short-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | $ 168,387,108 | $ 147,522,581
ProShares VIX Mid-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 34,013,638 | 44,197,990
ProShares Short VIX Short-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 864,378,556 | 160,086,825
ProShares Ultra VIX Short-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 419,552,069 | 426,699,558
ProShares UltraShort Bloomberg Crude Oil [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 227,620,440 | 192,060,689
Pro Shares UltraPro 3X Short Crude Oil ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (2,423,370) |
ProShares UltraShort Bloomberg Natural Gas [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,347,218 | 2,417,120
ProShares UltraShort Gold [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 37,892,152 | 63,593,101
ProShares UltraShort Silver [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 20,123,602 | 22,961,875
ProShares Short Euro [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 6,104,639 | 13,297,728
ProShares UltraShort Australian Dollar [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 8,377,401 | 14,091,959
ProShares UltraShort Euro [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 223,584,243 | 353,538,718
ProShares UltraShort Yen [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 147,065,796 | 273,847,250
ProShares Ultra Bloomberg Crude Oil [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 616,974,290 | 945,945,743
Proshares Ultra Pro 3X Crude Oil ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 1,272,779 |
ProShares Ultra Bloomberg Natural Gas [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 41,948,242 | 38,720,368
ProShares Ultra Gold [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 93,456,673 | 90,906,554
ProShares Ultra Silver [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 242,380,783 | 274,297,250
ProShares Ultra Euro [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 10,786,405 | 11,317,821
ProShares Ultra Yen [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 4,267,102 | 4,940,803
Total Trust [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,169,109,766 | 3,080,443,933
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares VIX Short-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 186,716,429 | 147,991,233
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares VIX Mid-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 35,955,278 | 45,486,235
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares Short VIX Short-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 770,134,521 | 170,396,436
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares Ultra VIX Short-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 521,315,100 | 434,671,795
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares UltraShort Bloomberg Crude Oil [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 246,666,306 | 205,694,385
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares UltraShort Bloomberg Natural Gas [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 2,998,697 | 2,899,151
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares UltraShort Gold [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 34,940,087 | 60,540,555
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares UltraShort Silver [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 17,966,229 | 21,550,319
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares Short Euro [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 5,998,433 | 13,164,828
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares UltraShort Australian Dollar [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 7,997,911 | 12,909,619
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares UltraShort Euro [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 219,684,550 | 337,375,787
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares UltraShort Yen [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 137,818,917 | 257,102,313
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares Ultra Bloomberg Crude Oil [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 562,359,737 | 885,050,007
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares Ultra Bloomberg Natural Gas [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 42,919,932 | 36,183,648
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares Ultra Gold [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 101,900,580 | 95,356,621
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares Ultra Silver [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 270,629,525 | 295,300,799
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares Ultra Euro [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 10,995,765 | 11,891,831
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | ProShares Ultra Yen [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 4,662,411 | 5,282,879
Level I - Quoted Prices [Member] | Short-Term U.S. Government and Agencies [Member] | Total Trust [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,181,660,408 | 3,038,848,441
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares VIX Short-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (18,329,321) | (468,652)
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares VIX Mid-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (1,941,640) | (1,288,245)
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares Short VIX Short-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 94,244,035 | (10,309,611)
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares Ultra VIX Short-Term Futures ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (101,763,031) | (7,972,237)
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares UltraShort Bloomberg Crude Oil [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (5,367,489) | (1,426,815)
Level I - Quoted Prices [Member] | Futures Contracts [Member] | Pro Shares UltraPro 3X Short Crude Oil ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (2,423,370) |
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares UltraShort Bloomberg Natural Gas [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 348,521 | (482,031)
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares UltraShort Gold [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (9,540) | 18,980
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares UltraShort Silver [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 4,940 | 27,310
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares Short Euro [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 106,206 | 132,900
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares UltraShort Australian Dollar [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 379,490 | 1,182,340
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares Ultra Bloomberg Crude Oil [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 13,817,653 | 5,537,165
Level I - Quoted Prices [Member] | Futures Contracts [Member] | Proshares Ultra Pro 3X Crude Oil ETF [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 1,272,779 |
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares Ultra Bloomberg Natural Gas [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (971,690) | 2,536,720
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares Ultra Gold [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 9,520 | (18,960)
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares Ultra Silver [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (4,940) | (27,360)
Level I - Quoted Prices [Member] | Futures Contracts [Member] | Total Trust [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (20,627,877) | (12,558,496)
Level II - Other Significant Observable Inputs [Member] | Forward Agreements [Member] | ProShares UltraShort Gold [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 2,961,605 | 3,033,566
Level II - Other Significant Observable Inputs [Member] | Forward Agreements [Member] | ProShares UltraShort Silver [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 2,152,433 | 1,384,246
Level II - Other Significant Observable Inputs [Member] | Forward Agreements [Member] | ProShares Ultra Gold [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (8,453,427) | (4,431,107)
Level II - Other Significant Observable Inputs [Member] | Forward Agreements [Member] | ProShares Ultra Silver [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (28,243,802) | (20,976,189)
Level II - Other Significant Observable Inputs [Member] | Forward Agreements [Member] | Total Trust [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (31,583,191) | (20,989,484)
Level II - Other Significant Observable Inputs [Member] | Foreign Currency Forward Contracts [Member] | ProShares UltraShort Euro [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 3,899,693 | 16,162,931
Level II - Other Significant Observable Inputs [Member] | Foreign Currency Forward Contracts [Member] | ProShares UltraShort Yen [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 9,246,879 | 16,744,937
Level II - Other Significant Observable Inputs [Member] | Foreign Currency Forward Contracts [Member] | ProShares Ultra Euro [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (209,360) | (574,010)
Level II - Other Significant Observable Inputs [Member] | Foreign Currency Forward Contracts [Member] | ProShares Ultra Yen [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (395,309) | (342,076)
Level II - Other Significant Observable Inputs [Member] | Foreign Currency Forward Contracts [Member] | Total Trust [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 12,541,903 | 31,991,782
Level II - Other Significant Observable Inputs [Member] | Swap Agreements [Member] | ProShares UltraShort Bloomberg Crude Oil [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | (13,678,377) | (12,206,881)
Level II - Other Significant Observable Inputs [Member] | Swap Agreements [Member] | ProShares Ultra Bloomberg Crude Oil [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | 40,796,900 | 55,358,571
Level II - Other Significant Observable Inputs [Member] | Swap Agreements [Member] | Total Trust [Member] |  |
Significant Accounting Policies [Line Items] |  |
Investments, fair value disclosure | $ 27,118,523 | $ 43,151,690

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