Investments - Gross Amounts Not Offset in Statements of Financial Condition (Detail) (USD $)	Mar. 31, 2015	Mar. 31, 2014
ProShares UltraShort Gold [Member] \| Deutsche Bank AG [Member]
Derivative [Line Items]
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	$ (647,913)	$ (1,422,997)
Financial Instruments for the Benefit of /the Counterparties	647,913	1,422,997
Cash Collateral for the Benefit of / the Counterparties	0	0
Net Amount	0	0
ProShares UltraShort Gold [Member] \| Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(370,015)	(354,660)
Financial Instruments for the Benefit of /the Counterparties	370,015	354,660
Cash Collateral for the Benefit of / the Counterparties	0	0
Net Amount	0	0
ProShares UltraShort Gold [Member] \| Societe Generale S.A. [Member]
Derivative [Line Items]
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(375,583)	(182,225)
Financial Instruments for the Benefit of /the Counterparties	375,583	182,225
Cash Collateral for the Benefit of / the Counterparties	0	0
Net Amount	0	0
ProShares UltraShort Gold [Member] \| UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(188,570)	(322,896)
Financial Instruments for the Benefit of /the Counterparties	188,570	322,896
Cash Collateral for the Benefit of / the Counterparties	0	0
Net Amount	0	0
ProShares UltraShort Silver [Member] \| Deutsche Bank AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		462,619
Cash Collateral for the Funds / the Counterparties		(462,619)
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(1,877,505)
Financial Instruments for the Benefit of /the Counterparties	1,877,505
Cash Collateral for the Benefit of / the Counterparties	0
Net Amount	0
ProShares UltraShort Silver [Member] \| Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		138,563
Financial Instruments for the Funds /the Counterparties		(138,563)
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(860,699)
Financial Instruments for the Benefit of /the Counterparties	860,699
Cash Collateral for the Benefit of / the Counterparties	0
Net Amount	0
ProShares UltraShort Silver [Member] \| Societe Generale S.A. [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition		198,341
Financial Instruments for the Funds /the Counterparties		(198,341)
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(296,399)
Financial Instruments for the Benefit of /the Counterparties	296,399
Cash Collateral for the Benefit of / the Counterparties	0
Net Amount	0
ProShares UltraShort Silver [Member] \| UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(701,580)	(204,570)
Financial Instruments for the Benefit of /the Counterparties	701,580	204,570
Cash Collateral for the Benefit of / the Counterparties	0	0
Net Amount	0	0
ProShares Ultra Bloomberg Commodity [Member] \| Deutsche Bank AG [Member]
Derivative [Line Items]
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(54,521)	(143,751)
Financial Instruments for the Benefit of /the Counterparties	54,521	143,751
Cash Collateral for the Benefit of / the Counterparties	0	0
Net Amount	0	0
ProShares Ultra Bloomberg Commodity [Member] \| Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(55,872)	(138,532)
Financial Instruments for the Benefit of /the Counterparties	55,872	138,532
Cash Collateral for the Benefit of / the Counterparties	0	0
Net Amount	0	0
ProShares Ultra Bloomberg Commodity [Member] \| UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(19,040)	(49,055)
Financial Instruments for the Benefit of /the Counterparties	19,040	49,055
Cash Collateral for the Benefit of / the Counterparties	0	0
Net Amount	0	0
ProShares Ultra Bloomberg Crude Oil [Member] \| Deutsche Bank AG [Member]
Derivative [Line Items]
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(24,270,565)	(24,223,667)
Financial Instruments for the Benefit of /the Counterparties	24,270,565	24,223,667
Cash Collateral for the Benefit of / the Counterparties	0	0
Net Amount	0	0
ProShares Ultra Bloomberg Crude Oil [Member] \| Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(24,277,344)	(24,285,701)
Financial Instruments for the Benefit of /the Counterparties	24,277,344	24,285,701
Cash Collateral for the Benefit of / the Counterparties	0	0
Net Amount	0	0
ProShares Ultra Bloomberg Crude Oil [Member] \| Societe Generale S.A. [Member]
Derivative [Line Items]
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(8,155,514)	(5,528,160)
Financial Instruments for the Benefit of /the Counterparties	8,155,514	5,528,160
Cash Collateral for the Benefit of / the Counterparties	0	0
Net Amount	0	0
ProShares Ultra Bloomberg Crude Oil [Member] \| UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(21,770,796)	(22,143,569)
Financial Instruments for the Benefit of /the Counterparties	21,770,796	22,143,569
Cash Collateral for the Benefit of / the Counterparties	0	0
Net Amount	0	0
ProShares Ultra Euro [Member] \| Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(361,029)	(38,856)
Financial Instruments for the Benefit of /the Counterparties	361,029	38,856
Cash Collateral for the Benefit of / the Counterparties	0	0
Net Amount	0	0
ProShares Ultra Euro [Member] \| UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(417,721)	(64,515)
Financial Instruments for the Benefit of /the Counterparties	417,721	64,515
Cash Collateral for the Benefit of / the Counterparties	0	0
Net Amount	0	0
ProShares Ultra Yen [Member] \| Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(15,605)	(12,255)
Financial Instruments for the Benefit of /the Counterparties	15,605	12,255
Cash Collateral for the Benefit of / the Counterparties	0	0
Net Amount	0	0
ProShares Ultra Yen [Member] \| UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Liabilities presented in the Statements of Financial Condition	(25,573)	(2,990)
Financial Instruments for the Benefit of /the Counterparties	25,573	2,990
Cash Collateral for the Benefit of / the Counterparties	0	0
Net Amount	0	0
ProShares UltraShort Yen [Member] \| Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	446,692
Financial Instruments for the Funds /the Counterparties	(446,692)
Amounts of Recognized Liabilities presented in the Statements of Financial Condition		(1,466,239)
Financial Instruments for the Benefit of /the Counterparties		1,466,239
Cash Collateral for the Benefit of / the Counterparties		0
Net Amount		0
ProShares UltraShort Yen [Member] \| UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	221,065
Financial Instruments for the Funds /the Counterparties	(221,065)
Amounts of Recognized Liabilities presented in the Statements of Financial Condition		(112,536)
Financial Instruments for the Benefit of /the Counterparties		112,536
Cash Collateral for the Benefit of / the Counterparties		0
Net Amount		0
ProShares Ultra Silver [Member] \| Deutsche Bank AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	12,075,006
Cash Collateral for the Funds / the Counterparties	(12,075,006)
Amounts of Recognized Liabilities presented in the Statements of Financial Condition		(6,220,069)
Financial Instruments for the Benefit of /the Counterparties		6,220,069
Cash Collateral for the Benefit of / the Counterparties		0
Net Amount		0
ProShares Ultra Silver [Member] \| Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	4,343,236
Financial Instruments for the Funds /the Counterparties	(4,343,236)
Amounts of Recognized Liabilities presented in the Statements of Financial Condition		(2,124,796)
Financial Instruments for the Benefit of /the Counterparties		2,124,796
Cash Collateral for the Benefit of / the Counterparties		0
Net Amount		0
ProShares Ultra Silver [Member] \| Societe Generale S.A. [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	2,548,949
Financial Instruments for the Funds /the Counterparties	(2,548,949)
Amounts of Recognized Liabilities presented in the Statements of Financial Condition		(1,384,207)
Financial Instruments for the Benefit of /the Counterparties		1,384,207
Cash Collateral for the Benefit of / the Counterparties		0
Net Amount		0
ProShares Ultra Silver [Member] \| UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	3,653,677
Financial Instruments for the Funds /the Counterparties	(3,653,677)
Amounts of Recognized Liabilities presented in the Statements of Financial Condition		(2,666,048)
Financial Instruments for the Benefit of /the Counterparties		2,666,048
Cash Collateral for the Benefit of / the Counterparties		0
Net Amount		0
ProShares UltraShort Bloomberg Commodity [Member] \| Deutsche Bank AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	118,941	243,474
Net Amount	118,941	243,474
ProShares UltraShort Bloomberg Commodity [Member] \| Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	113,070	240,271
Net Amount	113,070	240,271
ProShares UltraShort Bloomberg Commodity [Member] \| UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	44,614	83,514
Net Amount	44,614	83,514
ProShares UltraShort Bloomberg Crude Oil [Member] \| Deutsche Bank AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	9,502,897	7,669,493
Cash Collateral for the Funds / the Counterparties	(6,400,000)	(6,800,000)
Net Amount	3,102,897	869,493
ProShares UltraShort Bloomberg Crude Oil [Member] \| Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	7,090,832	8,362,336
Financial Instruments for the Funds /the Counterparties	(4,179,789)	(7,598,657)
Net Amount	2,911,043	763,679
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	2,850,353	2,132,657
Financial Instruments for the Funds /the Counterparties	(2,850,353)	(2,132,657)
ProShares UltraShort Bloomberg Crude Oil [Member] \| UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	7,413,391	8,853,591
Financial Instruments for the Funds /the Counterparties	(4,951,884)	(8,281,350)
Net Amount	2,461,507	572,241
ProShares UltraShort Euro [Member] \| Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	11,076,250	8,193,303
Financial Instruments for the Funds /the Counterparties	(7,250,046)	(6,008,925)
Net Amount	3,826,204	2,184,378
ProShares UltraShort Euro [Member] \| UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	12,313,945	8,569,691
Financial Instruments for the Funds /the Counterparties	(9,399,102)	(6,592,366)
Cash Collateral for the Funds / the Counterparties		(11,518)
Net Amount	2,914,843	1,965,807
ProShares Ultra Gold [Member] \| Deutsche Bank AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	895,425	1,231,694
Cash Collateral for the Funds / the Counterparties	(800,000)	(1,231,694)
Net Amount	95,425
ProShares Ultra Gold [Member] \| Goldman Sachs International [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	346,843	222,126
Financial Instruments for the Funds /the Counterparties	(311,985)
Net Amount	34,858	222,126
ProShares Ultra Gold [Member] \| Societe Generale S.A. [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	90,113	190,591
Financial Instruments for the Funds /the Counterparties	(90,113)	(190,591)
ProShares Ultra Gold [Member] \| UBS AG [Member]
Derivative [Line Items]
Amounts of Recognized Assets presented in the Statements of Financial Condition	328,587	406,743
Financial Instruments for the Funds /the Counterparties	(302,741)	(406,743)
Net Amount	$ 25,846

Investments - Gross Amounts Not Offset in Statements of Financial Condition (Detail) (USD $)

Mar. 31, 2015

Mar. 31, 2014

ProShares UltraShort Gold [Member] | Deutsche Bank AG [Member]

Derivative [Line Items]

Amounts of Recognized Liabilities presented in the Statements of Financial Condition

$ (647,913)

$ (1,422,997)

Financial Instruments for the Benefit of /the Counterparties

647,913

1,422,997

Cash Collateral for the Benefit of / the Counterparties