Significant Accounting Policies - Valuation of Investments using Fair Value Hierarchy (Detail) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
ProShares VIX Short-Term Futures ETF [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	$ 147,522,581	$ 94,995,034
ProShares VIX Mid-Term Futures ETF [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	44,197,990	25,631,927
ProShares Short VIX Short-Term Futures ETF [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	160,086,825	546,139,133
ProShares Ultra VIX Short-Term Futures ETF [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	426,699,558	450,252,315
ProShares UltraShort Bloomberg Crude Oil [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	192,060,689	88,569,811
ProShares UltraShort Bloomberg Natural Gas [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	2,417,120	5,643,840
ProShares UltraShort Gold [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	63,593,101	74,794,067
ProShares UltraShort Silver [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	22,961,875	55,514,479
ProShares Short Euro [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	13,297,728	15,396,649
ProShares UltraShort Australian Dollar [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	14,091,959	17,988,624
ProShares UltraShort Euro [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	353,538,718	517,456,440
ProShares UltraShort Yen [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	273,847,250	246,101,549
ProShares Ultra Bloomberg Crude Oil [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	945,945,743	707,544,640
ProShares Ultra Bloomberg Natural Gas [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	38,720,368	33,120,610
ProShares Ultra Gold [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	90,906,554	69,656,792
ProShares Ultra Silver [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	274,297,250	216,329,495
ProShares Ultra Euro [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	11,317,821	12,210,182
ProShares Ultra Yen [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	4,940,803	5,330,802
Total Trust [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	3,080,443,933	3,182,676,389
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	147,991,233	96,073,659
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	45,486,235	25,976,287
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	170,396,436	535,392,718
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	434,671,795	438,357,849
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	205,694,385	79,692,642
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	2,899,151	8,115,004
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	60,540,555	72,979,905
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	21,550,319	50,730,230
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	13,164,828	15,153,211
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	12,909,619	18,408,894
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	337,375,787	546,166,776
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	257,102,313	259,997,001
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	885,050,007	797,650,543
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	36,183,648	26,807,731
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	95,356,621	71,912,587
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	295,300,799	238,899,626
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	11,891,831	11,605,262
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	5,282,879	5,069,491
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	3,038,848,441	3,298,989,416
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares VIX Short-Term Futures ETF [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	(468,652)	(1,078,625)
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares VIX Mid-Term Futures ETF [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	(1,288,245)	(344,360)
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	(10,309,611)	10,746,415
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	(7,972,237)	11,894,466
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares UltraShort Bloomberg Crude Oil [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	(1,426,815)	2,464,513
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares UltraShort Bloomberg Natural Gas [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	(482,031)	(2,471,164)
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares UltraShort Gold [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	18,980	5,220
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares UltraShort Silver [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	27,310	5,970
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares Short Euro [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	132,900	243,438
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares UltraShort Australian Dollar [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	1,182,340	(420,270)
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares Ultra Bloomberg Crude Oil [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	5,537,165	(17,929,314)
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares Ultra Bloomberg Natural Gas [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	2,536,720	6,312,879
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares Ultra Gold [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	(18,960)	(5,200)
Level I - Quoted Prices [Member] | Futures Contracts [Member] | ProShares Ultra Silver [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	(27,360)	(9,030)
Level I - Quoted Prices [Member] | Futures Contracts [Member] | Total Trust [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	(12,558,496)	9,414,938
Level II - Other Significant Observable Inputs [Member] | Forward Agreements [Member] | ProShares UltraShort Gold [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	3,033,566	1,808,942
Level II - Other Significant Observable Inputs [Member] | Forward Agreements [Member] | ProShares UltraShort Silver [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	1,384,246	4,778,279
Level II - Other Significant Observable Inputs [Member] | Forward Agreements [Member] | ProShares Ultra Gold [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	(4,431,107)	(2,250,595)
Level II - Other Significant Observable Inputs [Member] | Forward Agreements [Member] | ProShares Ultra Silver [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	(20,976,189)	(22,561,101)
Level II - Other Significant Observable Inputs [Member] | Forward Agreements [Member] | Total Trust [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	(20,989,484)	(18,224,475)
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	16,162,931	(28,710,336)
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	16,744,937	(13,895,452)
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	(574,010)	604,920
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	(342,076)	261,311
Level II - Other Significant Observable Inputs [Member] | Foreign Currency Forward Contracts [Member] | Total Trust [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	31,991,782	(41,739,557)
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	(12,206,881)	6,412,656
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	55,358,571	(72,176,589)
Level II - Other Significant Observable Inputs [Member] | Swap Agreements [Member] | Total Trust [Member]
Significant Accounting Policies [Line Items]
Investments, fair value disclosure	$ 43,151,690	$ (65,763,933)