v2.4.1.9

Agreements - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015
Health Care Trust Fund [Line Items]
Ceiling for legal fees	$ 100,000ck0001415311_CeilingForFeePaidToAdministrativeAndLegalFacilitators
Percentage of annual NAV as limit to pay SEC registration fees incurred	0.021%ck0001415311_PercentageOfAnnualNavOfFund
Ceiling for per annum K-1 preparation and mailing fees against annual net assets of Fund	0.10%ck0001415311_CeilingForPreparationAndMailingFee
Managed Futures Fund [Member]
Health Care Trust Fund [Line Items]
Management Fee paid to sponsor, percent per annum of the average daily NAV of each Geared Fund	0.75%ck0001415311_PercentageOfAverageDailyNavOfFund / us-gaap_InvestmentTypeAxis = ck0001415311_ManagedFuturesFundMember
Leverage Fund [Member]
Health Care Trust Fund [Line Items]
Management Fee paid to sponsor, percent per annum of the average daily NAV of each Geared Fund	0.95%ck0001415311_PercentageOfAverageDailyNavOfFund / us-gaap_HealthCareTrustFundAxis = ck0001415311_LeverageFundMember
Geared VIX Fund [Member]
Health Care Trust Fund [Line Items]
Management Fee paid to sponsor, percent per annum of the average daily NAV of each Geared Fund	0.95%ck0001415311_PercentageOfAverageDailyNavOfFund / us-gaap_HealthCareTrustFundAxis = ck0001415311_GearedVixFundMember
Short Euro Fund [Member]
Health Care Trust Fund [Line Items]
Management Fee paid to sponsor, percent per annum of the average daily NAV of each Geared Fund	0.95%ck0001415311_PercentageOfAverageDailyNavOfFund / us-gaap_HealthCareTrustFundAxis = ck0001415311_ShortFundMember
Volatility Index Fund [Member]
Health Care Trust Fund [Line Items]
Management Fee paid to sponsor, percent per annum of the average daily NAV of each Geared Fund	0.85%ck0001415311_PercentageOfAverageDailyNavOfFund / us-gaap_HealthCareTrustFundAxis = ck0001415311_VolatilityIndexFundMember

X

- Definition

Ceiling for fee paid to administrative and legal facilitators.

+ References

No definition available.

+ Details

Name:	ck0001415311_CeilingForFeePaidToAdministrativeAndLegalFacilitators
Namespace Prefix:	ck0001415311_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Ceiling for preparation and mailing fee of K-1.

+ References

No definition available.

+ Details

Name:	ck0001415311_CeilingForPreparationAndMailingFee
Namespace Prefix:	ck0001415311_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Percentage of annual NAV of fund.

+ References

No definition available.

+ Details

Name:	ck0001415311_PercentageOfAnnualNavOfFund
Namespace Prefix:	ck0001415311_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Percentage of average daily NAV of fund.

+ References

No definition available.

+ Details

Name:	ck0001415311_PercentageOfAverageDailyNavOfFund
Namespace Prefix:	ck0001415311_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Details

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

X

- Details

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

X

- Details

Name:	us-gaap_HealthCareTrustFundAxis=ck0001415311_LeverageFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_HealthCareTrustFundAxis=ck0001415311_ShortFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_HealthCareTrustFundAxis=ck0001415311_VolatilityIndexFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_InvestmentTypeAxis=ck0001415311_ManagedFuturesFundMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: