v2.4.1.9

Subsequent Events - Additional Information (Detail)	3 Months Ended	0 Months Ended
	Mar. 31, 2015	May 01, 2015	May 20, 2015
Subsequent Event [Line Items]
Shares reverse split, description	There were no reverse Share splits during the three months ended March 31, 2015.
Shares reverse split ratio	0us-gaap_StockholdersEquityNoteStockSplitConversionRatio1
Subsequent Event [Member]
Subsequent Event [Line Items]
Shares reverse split, description		The reverse splits will increase the price per Share of each Fund with a proportionate decrease in the number of Shares outstanding. For example, for a 1-for-4 reverse split, every four pre-split Shares will result in the receipt of one post-split Share, which will be priced four times higher than the NAV of a pre-split Share.
ProShares Ultra Bloomberg Commodity [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Shares reverse split, description		1-for-4 reverse split of the Shares
Shares reverse split ratio		0.25us-gaap_StockholdersEquityNoteStockSplitConversionRatio1 / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCommodityMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember	0.25us-gaap_StockholdersEquityNoteStockSplitConversionRatio1 / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCommodityMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember
ProShares Ultra Bloomberg Natural Gas [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Shares reverse split, description		1-for-4 reverse split of the Shares
Shares reverse split ratio		0.25us-gaap_StockholdersEquityNoteStockSplitConversionRatio1 / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergNaturalGasMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember	0.25us-gaap_StockholdersEquityNoteStockSplitConversionRatio1 / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergNaturalGasMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember
ProShares Ultra Yen [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Shares reverse split, description		1-for-4 reverse split of the Shares
Shares reverse split ratio		0.25us-gaap_StockholdersEquityNoteStockSplitConversionRatio1 / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember	0.25us-gaap_StockholdersEquityNoteStockSplitConversionRatio1 / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraYenMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember
ProShares Ultra VIX Short-Term Futures ETF [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Shares reverse split, description		1-for-5 reverse split of the Shares
Shares reverse split ratio		0.20us-gaap_StockholdersEquityNoteStockSplitConversionRatio1 / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember	0.20us-gaap_StockholdersEquityNoteStockSplitConversionRatio1 / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraVixShortTermFuturesEtfMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember
ProShares Ultra Bloomberg Crude Oil [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Shares reverse split, description		1-for-5 reverse split of the Shares
Shares reverse split ratio		0.20us-gaap_StockholdersEquityNoteStockSplitConversionRatio1 / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCrudeOilMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember	0.20us-gaap_StockholdersEquityNoteStockSplitConversionRatio1 / us-gaap_StatementBusinessSegmentsAxis = ck0001415311_ProsharesUltraBloombergCrudeOilMember / us-gaap_SubsequentEventTypeAxis = us-gaap_SubsequentEventMember

X

- Definition

Ratio applied to the conversion of stock split, for example but not limited to, one share converted to two or two shares converted to one.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Stock Split

-URI http://asc.fasb.org/extlink&oid=6525746



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 4

-Subparagraph (SAB TOPIC 4.C)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770

+ Details

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X

- Definition

Description of the reverse stock split arrangement. Also provide the retroactive effect given by the reverse split that occurs after the balance sheet date but before the release of financial statements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 4

-Subparagraph (SAB TOPIC 4.C)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187143-122770



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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 4

-Section C

+ Details

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