Investments - Gross Amounts Not Offset in Statements of Financial Condition (Detail) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
ProShares UltraShort Gold [Member] | Deutsche Bank AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		$ 1,046,664
Cash Collateral for the Benefit of (the Funds) / the Counterparties		(1,046,664)
ProShares UltraShort Gold [Member] | Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	$ 881,454	158,827
Financial Instruments for the Benefit of (the Funds) / the Counterparties	(874,948)
Net Amounts of Assets presented in the Statements of Financial Condition	6,506	158,827
ProShares UltraShort Gold [Member] | Societe Generale S.A. [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	393,006	212,680
Financial Instruments for the Benefit of (the Funds) / the Counterparties	(393,006)	(212,680)
ProShares UltraShort Gold [Member] | UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	611,295	386,856
Financial Instruments for the Benefit of (the Funds) / the Counterparties		(386,856)
Cash Collateral for the Benefit of (the Funds) / the Counterparties	(611,295)
ProShares UltraShort Gold [Member] | Citibank N.A. [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	1,147,811	3,915
Net Amounts of Assets presented in the Statements of Financial Condition	1,147,811	3,915
ProShares UltraShort Silver [Member] | Deutsche Bank AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		2,500,263
Cash Collateral for the Benefit of (the Funds) / the Counterparties		(2,500,000)
Net Amounts of Assets presented in the Statements of Financial Condition		263
ProShares UltraShort Silver [Member] | Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	323,829	1,044,986
Financial Instruments for the Benefit of (the Funds) / the Counterparties	(323,829)	(858,460)
Net Amounts of Assets presented in the Statements of Financial Condition		186,526
ProShares UltraShort Silver [Member] | Societe Generale S.A. [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	86,543	438,975
Financial Instruments for the Benefit of (the Funds) / the Counterparties	(86,543)	(438,975)
ProShares UltraShort Silver [Member] | UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	363,396	794,055
Financial Instruments for the Benefit of (the Funds) / the Counterparties		(582,692)
Cash Collateral for the Benefit of (the Funds) / the Counterparties	(363,396)
Net Amounts of Assets presented in the Statements of Financial Condition		211,363
ProShares UltraShort Silver [Member] | Citibank N.A. [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	610,478
Net Amounts of Assets presented in the Statements of Financial Condition	610,478
ProShares UltraShort Yen [Member] | Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	8,256,779
Financial Instruments for the Benefit of (the Funds) / the Counterparties	(7,771,819)
Net Amounts of Assets presented in the Statements of Financial Condition	484,960
Amounts of Recognized Assets presented in the Statements of Financial Condition		(6,470,405)
Financial Instruments for the Benefit of (the Funds) / the Counterparties		6,470,405
Cash Collateral for the Benefit of (the Funds) / the Counterparties		0
ProShares UltraShort Yen [Member] | UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	8,488,158
Cash Collateral for the Benefit of (the Funds) / the Counterparties	(7,980,000)
Net Amounts of Assets presented in the Statements of Financial Condition	508,158
Amounts of Recognized Assets presented in the Statements of Financial Condition		(7,425,047)
Financial Instruments for the Benefit of (the Funds) / the Counterparties		7,425,047
Cash Collateral for the Benefit of (the Funds) / the Counterparties		0
ProShares Ultra Bloomberg Crude Oil [Member] | Deutsche Bank AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		(20,221,872)
Financial Instruments for the Benefit of (the Funds) / the Counterparties		20,221,872
Cash Collateral for the Benefit of (the Funds) / the Counterparties		0
ProShares Ultra Bloomberg Crude Oil [Member] | Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		(20,806,119)
Financial Instruments for the Benefit of (the Funds) / the Counterparties		20,806,119
Cash Collateral for the Benefit of (the Funds) / the Counterparties		0
ProShares Ultra Bloomberg Crude Oil [Member] | Societe Generale S.A. [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		(6,357,459)
Financial Instruments for the Benefit of (the Funds) / the Counterparties		6,357,459
Cash Collateral for the Benefit of (the Funds) / the Counterparties		0
ProShares Ultra Bloomberg Crude Oil [Member] | UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		(22,281,150)
Financial Instruments for the Benefit of (the Funds) / the Counterparties		22,281,150
Cash Collateral for the Benefit of (the Funds) / the Counterparties		0
ProShares Ultra Bloomberg Crude Oil [Member] | Citibank N.A. [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		(2,509,989)
Financial Instruments for the Benefit of (the Funds) / the Counterparties		2,509,989
Cash Collateral for the Benefit of (the Funds) / the Counterparties		0
ProShares Ultra Silver [Member] | Deutsche Bank AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		(9,355,945)
Financial Instruments for the Benefit of (the Funds) / the Counterparties		9,355,945
Cash Collateral for the Benefit of (the Funds) / the Counterparties		0
ProShares Ultra Silver [Member] | Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	(5,869,092)	(5,106,853)
Financial Instruments for the Benefit of (the Funds) / the Counterparties	5,869,092	5,106,853
Cash Collateral for the Benefit of (the Funds) / the Counterparties	0	0
ProShares Ultra Silver [Member] | Societe Generale S.A. [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	(2,532,729)	(2,704,459)
Financial Instruments for the Benefit of (the Funds) / the Counterparties	2,532,729	2,704,459
Cash Collateral for the Benefit of (the Funds) / the Counterparties	0	0
ProShares Ultra Silver [Member] | UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	(5,628,359)	(5,393,844)
Financial Instruments for the Benefit of (the Funds) / the Counterparties	5,628,359	5,393,844
Cash Collateral for the Benefit of (the Funds) / the Counterparties	0	0
ProShares Ultra Silver [Member] | Citibank N.A. [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	(6,946,009)
Financial Instruments for the Benefit of (the Funds) / the Counterparties	6,946,009
Cash Collateral for the Benefit of (the Funds) / the Counterparties	0
ProShares Ultra Euro [Member] | Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		315,354
Financial Instruments for the Benefit of (the Funds) / the Counterparties		(315,354)
Amounts of Recognized Assets presented in the Statements of Financial Condition	(239,256)
Financial Instruments for the Benefit of (the Funds) / the Counterparties	239,256
Cash Collateral for the Benefit of (the Funds) / the Counterparties	0
ProShares Ultra Euro [Member] | UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		289,566
Financial Instruments for the Benefit of (the Funds) / the Counterparties		(289,566)
Amounts of Recognized Assets presented in the Statements of Financial Condition	(334,754)
Financial Instruments for the Benefit of (the Funds) / the Counterparties	334,754
Cash Collateral for the Benefit of (the Funds) / the Counterparties	0
ProShares Ultra Yen [Member] | Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		169,787
Net Amounts of Assets presented in the Statements of Financial Condition		169,787
Amounts of Recognized Assets presented in the Statements of Financial Condition	(219,736)
Financial Instruments for the Benefit of (the Funds) / the Counterparties	219,736
Cash Collateral for the Benefit of (the Funds) / the Counterparties	0
ProShares Ultra Yen [Member] | UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		91,524
Net Amounts of Assets presented in the Statements of Financial Condition		91,524
Amounts of Recognized Assets presented in the Statements of Financial Condition	(122,340)
Financial Instruments for the Benefit of (the Funds) / the Counterparties	122,340
Cash Collateral for the Benefit of (the Funds) / the Counterparties	0
ProShares UltraShort Bloomberg Crude Oil [Member] | Deutsche Bank AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		1,722,894
Cash Collateral for the Benefit of (the Funds) / the Counterparties		(1,722,894)
ProShares UltraShort Bloomberg Crude Oil [Member] | Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	14,016,906	1,595,552
Financial Instruments for the Benefit of (the Funds) / the Counterparties	(14,016,906)	(1,595,552)
Amounts of Recognized Assets presented in the Statements of Financial Condition	(3,061,395)
Financial Instruments for the Benefit of (the Funds) / the Counterparties	3,061,395
Cash Collateral for the Benefit of (the Funds) / the Counterparties	0
ProShares UltraShort Bloomberg Crude Oil [Member] | Societe Generale S.A. [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	8,661,821	521,142
Financial Instruments for the Benefit of (the Funds) / the Counterparties	(8,661,821)	(521,142)
Amounts of Recognized Assets presented in the Statements of Financial Condition	(1,050,699)
Financial Instruments for the Benefit of (the Funds) / the Counterparties	1,050,699
Cash Collateral for the Benefit of (the Funds) / the Counterparties	0
ProShares UltraShort Bloomberg Crude Oil [Member] | UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	14,252,835	1,474,790
Financial Instruments for the Benefit of (the Funds) / the Counterparties		(1,474,790)
Cash Collateral for the Benefit of (the Funds) / the Counterparties	(14,252,835)
Amounts of Recognized Assets presented in the Statements of Financial Condition	(3,352,596)
Financial Instruments for the Benefit of (the Funds) / the Counterparties	3,352,596
Cash Collateral for the Benefit of (the Funds) / the Counterparties	0
ProShares UltraShort Bloomberg Crude Oil [Member] | Citibank N.A. [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	18,427,009	1,098,278
Net Amounts of Assets presented in the Statements of Financial Condition	18,427,009	1,098,278
Amounts of Recognized Assets presented in the Statements of Financial Condition	(4,742,191)
Financial Instruments for the Benefit of (the Funds) / the Counterparties	4,742,191
Cash Collateral for the Benefit of (the Funds) / the Counterparties	0
ProShares UltraShort Euro [Member] | Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	8,109,067
Financial Instruments for the Benefit of (the Funds) / the Counterparties	(8,109,067)
Amounts of Recognized Assets presented in the Statements of Financial Condition		(14,992,024)
Financial Instruments for the Benefit of (the Funds) / the Counterparties		14,992,024
Cash Collateral for the Benefit of (the Funds) / the Counterparties		0
ProShares UltraShort Euro [Member] | UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	8,053,864
Cash Collateral for the Benefit of (the Funds) / the Counterparties	(8,053,864)
Amounts of Recognized Assets presented in the Statements of Financial Condition		(13,718,312)
Financial Instruments for the Benefit of (the Funds) / the Counterparties		13,718,312
Cash Collateral for the Benefit of (the Funds) / the Counterparties		0
ProShares Ultra Gold [Member] | Deutsche Bank AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		(1,049,383)
Financial Instruments for the Benefit of (the Funds) / the Counterparties		1,049,383
Cash Collateral for the Benefit of (the Funds) / the Counterparties		0
ProShares Ultra Gold [Member] | Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	(1,112,916)	(520,730)
Financial Instruments for the Benefit of (the Funds) / the Counterparties	1,112,916	520,730
Cash Collateral for the Benefit of (the Funds) / the Counterparties	0	0
ProShares Ultra Gold [Member] | Societe Generale S.A. [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	(643,587)	(244,992)
Financial Instruments for the Benefit of (the Funds) / the Counterparties	643,587	244,992
Cash Collateral for the Benefit of (the Funds) / the Counterparties	0	0
ProShares Ultra Gold [Member] | UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	(1,209,622)	(430,876)
Financial Instruments for the Benefit of (the Funds) / the Counterparties	1,209,622	430,876
Cash Collateral for the Benefit of (the Funds) / the Counterparties	0	0
ProShares Ultra Gold [Member] | Citibank N.A. [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	(1,464,982)	(4,614)
Financial Instruments for the Benefit of (the Funds) / the Counterparties	1,464,982
Cash Collateral for the Benefit of (the Funds) / the Counterparties	$ 0	0
Net Amounts of Liabilities presented in the Statements of Financial Condition		$ (4,614)