v2.4.1.9

Agreements - Additional Information (Detail) (USD $) | 3 Months Ended
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Mar. 31, 2015
Health Care Trust Fund [Line Items] |
Ceiling for legal fees | $ 100,000 ck0001415311_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
Name: | us-gaap_HealthCareTrustFundLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_HealthCareTrustFundAxis=ck0001415311_GearedVixFundMember
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: |