Contracts And Agreements (Details Textual) (USD $)	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Minimum Amount Of Custody Fund Accounting And Fund Administration Services Payable	$ 75,000
Annual Fee Payable For Transfer Agency Services	20,000
Brokerage commissions	29,674	33,506	31,871
Rebalancing Cost	24,097	29,561	22,560
Percentage Of Rebalancing Cost	81.21%	88.23%	70.79%
Creation and Redemption Activity Costs	5,577	2,945	9,311
Percentage of Creation And Redemption Activity Costs	18.79%	8.79%	29.21%
Percentage Of Average Daily Assets Net Total	0.07%	0.06%	0.08%
Maximum [Member]
Transaction fees per transaction	15
Commission Per Round Turn	15
Minimum [Member]
Annual Fee Payable For Transfer Agency Services	75,000
Transaction fees per transaction	7
Commission Per Round Turn	7
First $500 Million Of The Related Public Funds’, Combined Net Assets [Member]
Fee percentage	0.06%
First $500 Million Of The Related Public Funds’, Combined Net Assets [Member] \| Maximum [Member]
Base amount for determining fee percentage	500,000,000
Related Public Funds’ Combined Net Assets Greater Than $500 Million But Less Than $1 Billion [Member]
Fee percentage	0.0465%
Related Public Funds’ Combined Net Assets Greater Than $500 Million But Less Than $1 Billion [Member] \| Maximum [Member]
Base amount for determining fee percentage	1,000,000,000
Related Public Funds’ Combined Net Assets Greater Than $500 Million But Less Than $1 Billion [Member] \| Minimum [Member]
Base amount for determining fee percentage	500,000,000
Related Public Funds’ Combined Net Assets Exceed $1 Billion [Member]
Fee percentage	0.035%
Related Public Funds’ Combined Net Assets Exceed $1 Billion [Member] \| Minimum [Member]
Base amount for determining fee percentage	1,000,000,000
Marketing Agreement [Member] \| BNO's assets up to $3 billion [Member]
Fee percentage	0.06%
Base amount for determining fee percentage	3,000,000,000
Marketing Agreement [Member] \| BNO's assets in excess of $3 billion [Member]
Fee percentage	0.04%
Base amount for determining fee percentage	$ 3,000,000,000

The annual fee payable for transfer agency services reported during the period.

No definition available.

Name:	bno_AnnualFeePayableForTransferAgencyServices
Namespace Prefix:	bno_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Base Fee Percentage

+ References

No definition available.

+ Details

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

- Definition

Basis Amount for Fee Percentage

+ References

No definition available.

+ Details

Name:	bno_BasisAmountForFeePercentage
Namespace Prefix:	bno_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the commissions round turn trade including exchange fees.

+ References

No definition available.

+ Details

Name:	bno_CommissionPerRoundTurn
Namespace Prefix:	bno_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of commission accrued as a result of trades necessitated by creation and redemption activity.

+ References

No definition available.

+ Details

Name:	bno_CreationAndRedemptionActivityCosts
Namespace Prefix:	bno_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The minimum amount of custody, fund accounting and fund administration services payable reported during the period.

+ References

No definition available.

+ Details

Name:	bno_MinimumAmountOfCustodyFundAccountingAndFundAdministrationServicesPayable
Namespace Prefix:	bno_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The percentage of average daily total net assets during the period.

+ References

No definition available.

+ Details

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

- Definition

The percentage of creation and redemption activity costs during the reporting period.

+ References

No definition available.

+ Details

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

- Definition

The percentage of rebalancing cost during the reporting period.

+ References

No definition available.

+ Details

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

- Definition

The amount attributable to commission accrued as a result of rebalancing costs during the reporting period.

+ References

No definition available.

+ Details

Name:	bno_RebalancingCost
Namespace Prefix:	bno_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Transaction Fees Paid.

+ References

No definition available.

+ Details

Name:	bno_TransactionFeesPaid
Namespace Prefix:	bno_
Data Type:	us-types:perUnitItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of expense during the period for floor brokerage fees paid to other broker-dealers to execute trades on their behalf, stock exchange fees, order flow fees, and clearance fees.

+ References

No definition available.

+ Details

Name:	us-gaap_FloorBrokerageExchangeAndClearanceFees
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration