XML 37 R4.htm IDEA: XBRL DOCUMENT v2.4.0.6

Condensed Schedule of Investments [Parenthetical]	6 Months Ended
	Jun. 30, 2012
Percentage Of United States Treasury Bill	0.09%

X

- Definition

Percentage of united states treasury bill.

+ References

No definition available.

+ Details

Name:	bno_PercentageOfUnitedStatesTreasuryBill
Namespace Prefix:	bno_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration