v3.8.0.1
Agreements - Additional Information (Detail)
 9 Months Ended
Sep. 30, 2017
USD ($)
Health Care Trust Fund [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%
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%
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%
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%
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%