v2.4.0.6

Schedule of Investments (Foreign Currency Forward Contracts) (Detail) (USD $)	Mar. 31, 2013
ProShares UltraShort Euro [Member] | Contracts To Purchase [Member]
Schedule of Investments [Line Items]
Unrealized Appreciation (Depreciation)	$ (1,439,211)	[1]
ProShares UltraShort Euro [Member] | Contracts To Sell [Member]
Schedule of Investments [Line Items]
Unrealized Appreciation (Depreciation)	15,104,660	[1]
ProShares UltraShort Euro [Member] | Euro with Goldman Sachs International [Member] | Contracts To Purchase [Member]
Schedule of Investments [Line Items]
Settlement Date	Apr. 05, 2013	[1]
Local Currency	34,213,200	[1]
Notional Amount at Value	43,854,981	[1]
Unrealized Appreciation (Depreciation)	(930,513)	[1]
ProShares UltraShort Euro [Member] | Euro with Goldman Sachs International [Member] | Contracts To Sell [Member]
Schedule of Investments [Line Items]
Settlement Date	Apr. 05, 2013	[1]
Local Currency	(396,944,825)	[1]
Notional Amount at Value	(508,809,688)	[1]
Unrealized Appreciation (Depreciation)	7,182,101	[1]
ProShares UltraShort Euro [Member] | Euro with UBS AG [Member] | Contracts To Purchase [Member]
Schedule of Investments [Line Items]
Settlement Date	Apr. 05, 2013	[1]
Local Currency	46,266,300	[1]
Notional Amount at Value	59,304,821	[1]
Unrealized Appreciation (Depreciation)	(508,698)	[1]
ProShares UltraShort Euro [Member] | Euro with UBS AG [Member] | Contracts To Sell [Member]
Schedule of Investments [Line Items]
Settlement Date	Apr. 05, 2013	[1]
Local Currency	(488,742,400)	[1]
Notional Amount at Value	(626,477,163)	[1]
Unrealized Appreciation (Depreciation)	7,922,559	[1]
ProShares UltraShort Yen [Member] | Contracts To Purchase [Member]
Schedule of Investments [Line Items]
Unrealized Appreciation (Depreciation)	769,747	[1]
ProShares UltraShort Yen [Member] | Contracts To Sell [Member]
Schedule of Investments [Line Items]
Unrealized Appreciation (Depreciation)	1,962,879	[1]
ProShares UltraShort Yen [Member] | Yen with Goldman Sachs International [Member] | Contracts To Purchase [Member]
Schedule of Investments [Line Items]
Settlement Date	Apr. 05, 2013	[1]
Local Currency	2,150,120,600	[1]
Notional Amount at Value	22,839,086	[1]
Unrealized Appreciation (Depreciation)	266,091	[1]
ProShares UltraShort Yen [Member] | Yen with Goldman Sachs International [Member] | Contracts To Sell [Member]
Schedule of Investments [Line Items]
Settlement Date	Apr. 05, 2013	[1]
Local Currency	(40,430,144,600)	[1]
Notional Amount at Value	(429,458,498)	[1]
Unrealized Appreciation (Depreciation)	956,014	[1]
ProShares UltraShort Yen [Member] | Yen with UBS AG [Member] | Contracts To Purchase [Member]
Schedule of Investments [Line Items]
Settlement Date	Apr. 05, 2013	[1]
Local Currency	6,684,643,600	[1]
Notional Amount at Value	71,005,855	[1]
Unrealized Appreciation (Depreciation)	503,656	[1]
ProShares UltraShort Yen [Member] | Yen with UBS AG [Member] | Contracts To Sell [Member]
Schedule of Investments [Line Items]
Settlement Date	Apr. 05, 2013	[1]
Local Currency	(57,256,267,400)	[1]
Notional Amount at Value	(608,189,529)	[1]
Unrealized Appreciation (Depreciation)	1,006,865	[1]
ProShares Ultra Euro [Member] | Contracts To Purchase [Member]
Schedule of Investments [Line Items]
Unrealized Appreciation (Depreciation)	(137,134)	[1]
ProShares Ultra Euro [Member] | Contracts To Sell [Member]
Schedule of Investments [Line Items]
Unrealized Appreciation (Depreciation)	3,138	[1]
ProShares Ultra Euro [Member] | Euro with Goldman Sachs International [Member] | Contracts To Purchase [Member]
Schedule of Investments [Line Items]
Settlement Date	Apr. 05, 2013	[1]
Local Currency	3,381,925	[1]
Notional Amount at Value	4,335,001	[1]
Unrealized Appreciation (Depreciation)	(63,478)	[1]
ProShares Ultra Euro [Member] | Euro with Goldman Sachs International [Member] | Contracts To Sell [Member]
Schedule of Investments [Line Items]
Settlement Date	Apr. 05, 2013	[1]
Local Currency	(66,800)	[1]
Notional Amount at Value	(85,625)	[1]
Unrealized Appreciation (Depreciation)	737	[1]
ProShares Ultra Euro [Member] | Euro with UBS AG [Member] | Contracts To Purchase [Member]
Schedule of Investments [Line Items]
Settlement Date	Apr. 05, 2013	[1]
Local Currency	4,109,500	[1]
Notional Amount at Value	5,267,617	[1]
Unrealized Appreciation (Depreciation)	(73,656)	[1]
ProShares Ultra Euro [Member] | Euro with UBS AG [Member] | Contracts To Sell [Member]
Schedule of Investments [Line Items]
Settlement Date	Apr. 05, 2013	[1]
Local Currency	(287,400)	[1]
Notional Amount at Value	(368,394)	[1]
Unrealized Appreciation (Depreciation)	2,401	[1]
ProShares Ultra Yen [Member] | Contracts To Purchase [Member]
Schedule of Investments [Line Items]
Unrealized Appreciation (Depreciation)	(58,146)	[1]
ProShares Ultra Yen [Member] | Contracts To Sell [Member]
Schedule of Investments [Line Items]
Unrealized Appreciation (Depreciation)	(12,416)	[1]
ProShares Ultra Yen [Member] | Yen with Goldman Sachs International [Member] | Contracts To Purchase [Member]
Schedule of Investments [Line Items]
Settlement Date	Apr. 05, 2013	[1]
Local Currency	359,404,200	[1]
Notional Amount at Value	3,817,676	[1]
Unrealized Appreciation (Depreciation)	(22,277)	[1]
ProShares Ultra Yen [Member] | Yen with Goldman Sachs International [Member] | Contracts To Sell [Member]
Schedule of Investments [Line Items]
Settlement Date	Apr. 05, 2013	[1]
Local Currency	(6,969,600)	[1]
Notional Amount at Value	(74,033)	[1]
Unrealized Appreciation (Depreciation)	(583)	[1]
ProShares Ultra Yen [Member] | Yen with UBS AG [Member] | Contracts To Purchase [Member]
Schedule of Investments [Line Items]
Settlement Date	Apr. 05, 2013	[1]
Local Currency	569,984,800	[1]
Notional Amount at Value	6,054,513	[1]
Unrealized Appreciation (Depreciation)	(35,869)	[1]
ProShares Ultra Yen [Member] | Yen with UBS AG [Member] | Contracts To Sell [Member]
Schedule of Investments [Line Items]
Settlement Date	Apr. 05, 2013	[1]
Local Currency	(250,806,500)	[1]
Notional Amount at Value	(2,664,126)	[1]
Unrealized Appreciation (Depreciation)	$ (11,833)	[1]
[1] The positions and counterparties herein are as of March 31, 2013. The Funds continually evaluate different counterparties for their transactions and counterparties are subject to change. New counterparties can be added at any time.

X

- Definition

Local Currency

+ References

No definition available.

+ Details

Name:	ck0001415311_LocalCurrency
Namespace Prefix:	ck0001415311_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Settlement Date

+ References

No definition available.

+ Details

Name:	ck0001415311_SettlementDate
Namespace Prefix:	ck0001415311_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	instant

X

- Definition

This element represents the fair value of the face or notional amount of a contract right or obligation that meets the definition of an asset or liability reported in the financial statements of the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 3

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Underlying

-URI http://asc.fasb.org/extlink&oid=6527499



Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 10

-Paragraph 1

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6431724&loc=d3e32938-113948



Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 20

-Section 10

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6438156&loc=d3e57880-113973

+ Details

Name:	us-gaap_InvestmentOwnedUnderlyingFaceAmountAtMarketValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

This element represents the net excess or deficiency of the fair value of an investment (security, contract) over or under its cost (face amount, notional amount), respectively, which excess value or deficiency has not been recognized in earnings of the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-INV

-Section Glossary

-IssueDate 2008-05-01

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_InvestmentOwnedUnrecognizedUnrealizedAppreciationDepreciationNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Details

Name:	us-gaap_ScheduleOfInvestmentsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration