v3.8.0.1

Financial Highlights - Per Share Operating Performance (Parenthetical) (Detail) | Sep. 30, 2017 $ / shares
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Pro Shares UltraPro 3X Short Crude Oil ETF [Member] |
Investment Company, Financial Highlights [Line Items] |
Returns for a share outstanding | $ 25.00

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- Definition Returns for share outstanding. + References No definition available. + Details
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Namespace Prefix: | ck0001415311_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraProThreeXShortCrudeOilEtfMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |