v3.8.0.1
Significant Accounting Policies - Valuation of Investments using Fair Value Hierarchy (Detail) - USD ($)
Sep. 30, 2017
Dec. 31, 2016
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