XML 41 R19.htm IDEA: XBRL DOCUMENT v2.4.0.6

FINANCIAL HIGHLIGHTS (Tables)

6 Months Ended

Jun. 30, 2012

Supplemental Financial Information Disclosure [Abstract]

Schedule Of Per Unit Peformance Data and Other Financial Data [Table Text Block]

The following table presents per unit performance data and other supplemental financial data for the six months ended June 30, 2012 and 2011 for the unitholders.  This information has been derived from information presented in the condensed financial statements.

		For the six months ended June 30, 2012 (Unaudited)				For the six months ended June 30, 2011 (Unaudited)
Per Unit Operating Performance:
Net asset value, beginning of period		$	74.54			$	63.08
Total income (loss)			(4.78	)			12.36
Total expenses			(0.39	)			(0.37	)
Net increase (decrease) in net asset value			(5.17	)			11.99
Net asset value, end of period		$	69.37			$	75.07
Total Return			(6.94	)%			19.01	%
Ratios to Average Net Assets
Total income (loss)			(5.93	)%			14.08	%
Management fees*			0.75	%			0.75	%
Total expenses excluding management fees*			0.30	%			0.66	%
Expenses waived*			(0.07	)%			(0.42	)%
Net expenses excluding management fees*			0.23	%			0.24	%
Net income (loss)			(6.42	)%			13.59	%

* Annualized

X

- Definition

Tabular disclosure of schedule of per unit peformance data and other financial data.

+ References

No definition available.

+ Details

Name:	bno_ScheduleOfPerUnitPeformanceDataAndOtherFinancialDataTableTextBlock
Namespace Prefix:	bno_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	bno_SupplementalFinancialInformationDisclosureAbstract
Namespace Prefix:	bno_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration