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Condensed Schedule of Investments [Parenthetical]	9 Months Ended
	Sep. 30, 2012
Percentage Of United States Treasury Bill	0.09%

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- 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