v2.4.0.8

Significant Accounting Policies - Additional Information (Detail) (Minimum [Member], Subsequent Event [Member], Matching VIX Funds [Member])	0 Months Ended
	Jul. 31, 2014
Minimum [Member] | Subsequent Event [Member] | Matching VIX Funds [Member]
Significant Accounting Policies [Line Items]
Percentage of brokerage commissions on contracts that exceed variable fees collected on average net assets	0.02%

X

- Definition

Percentage Of Brokerage Fees Based On Asset Value

+ References

No definition available.

+ Details

Name:	ck0001415311_PercentageOfBrokerageFeesBasedOnAssetValue
Namespace Prefix:	ck0001415311_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	ck0001415311_SignificantAccountingPoliciesLineItems
Namespace Prefix:	ck0001415311_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration