v2.4.0.8
Creation and Redemption of Creation Units - Additional Information (Detail)
3 Months Ended
Mar. 31, 2014
Creation And Redemption Of Creation Units [Line Items]  
Creation Unit, block Shares of a Fund 50,000
Fixed transaction fee per Creation Unit 500
Variable transaction fee, percent of the value of the Creation Unit, maximum 0.10%
Volatility Index Fund [Member]
 
Creation And Redemption Of Creation Units [Line Items]  
Creation Unit, block Shares of a Fund 25,000