v3.21.1

Agreements - Additional Information (Detail)	3 Months Ended
	Mar. 31, 2021 USD ($)
Investment Holdings [Line Items]
Ceiling for legal fees	$ 100,000
Percentage of annual NAV as limit to pay SEC registration fees incurred	0.021%
Ceiling for per annum K-1 preparation and mailing fees against annual net assets of Fund	0.10%
Leveraged Fund [Member]
Investment Holdings [Line Items]
Management Fee paid to sponsor, percent per annum of the average daily NAV of each Geared Fund	0.95%
GearedVix Funds [Member]
Investment Holdings [Line Items]
Management Fee paid to sponsor, percent per annum of the average daily NAV of each Geared Fund	0.95%
ProShares Short Euro [Member]
Investment Holdings [Line Items]
Management Fee paid to sponsor, percent per annum of the average daily NAV of each Geared Fund	0.95%
Matching VIX Funds [Member]
Investment Holdings [Line Items]
Management Fee paid to sponsor, percent per annum of the average daily NAV of each Geared Fund	0.85%

X

- Definition

Ceiling for fee paid to administrative and legal facilitators.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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X

- Definition

Ceiling for ongoing SEC registration fee of percentage of annual Nav.

+ References

No definition available.

+ Details

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X

- Definition

Ceiling for preparation and mailing fee of percentage of annual Nav.

+ References

No definition available.

+ Details

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Namespace Prefix:	ck0001415311_
Data Type:	num:percentItemType
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X

- Definition

Percentage of average daily NAV of fund.

+ References

No definition available.

+ Details

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Namespace Prefix:	ck0001415311_
Data Type:	num:percentItemType
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X

- 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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X

- Details

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X

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

X

- Details

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