v3.8.0.1

Financial Highlights - Per Share Operating Performance (Parenthetical) (Detail)	Sep. 30, 2017 $ / shares
Pro Shares UltraPro 3X Short Crude Oil ETF [Member]
Investment Company, Financial Highlights [Line Items]
Returns for a share outstanding	$ 25.00

X

- Definition

Returns for share outstanding.

+ References

No definition available.

+ Details

Name:	ck0001415311_ReturnsForShareOutstanding
Namespace Prefix:	ck0001415311_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

X

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=ck0001415311_ProsharesUltraProThreeXShortCrudeOilEtfMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: