Subsequent Events - Additional Information (Detail) - Subsequent Event [Member]	Jan. 12, 2017
ProShares UltraShort Bloomberg Crude Oil [Member]
Subsequent Event [Line Items]
Stockholders' equity, stock split conversion ratio	2
Stockholders' equity, stock split	2-for-1
ProShares Ultra Bloomberg Crude Oil [Member]
Subsequent Event [Line Items]
Stockholders' equity, reverse stock split conversion ratio	2
Stockholders' Equity, Reverse Stock Split	1-for-2
ProShares Ultra VIX Short-Term Futures ETF [Member]
Subsequent Event [Line Items]
Stockholders' equity, reverse stock split conversion ratio	5
Stockholders' Equity, Reverse Stock Split	1-for-5

Reverse stock split conversion ratio.

No definition available.

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- Definition

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

+ 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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- 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
-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 FASB
-Name Accounting Standards Codification
-Glossary Stock Split
-URI http://asc.fasb.org/extlink&oid=6525746

+ Details

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- 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

+ Details

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- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

No definition available.

+ Details

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- Details

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