Represents the number of residential parcels sold to date.

No definition available.

Name:	brn_NumberOfResidentialParcelsSold
Namespace Prefix:	brn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the number of single-family lots sold to date.

+ References

No definition available.

+ Details

Name:	brn_NumberOfSingleFamilyLotsSold
Namespace Prefix:	brn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

The gross cash inflow from the sale of interest in leasehold land.

+ References

No definition available.

+ Details

Name:	brn_ProceedsFromSaleOfInterestInLeaseholdLandGross
Namespace Prefix:	brn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Represents the period after purchase closing date the mortgage is due.

+ References

No definition available.

+ Details

Name:	brn_SignificantAcquisitionsAndDisposalsMortgagePeriodDueFromClosingDate
Namespace Prefix:	brn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the sale proceeds received by the entity in the significant acquisition or disposal.

+ References

No definition available.

+ Details

Name:	brn_SignificantAcquisitionsAndDisposalsNetSaleProceeds
Namespace Prefix:	brn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Represents the period after closing of agreement for final determination of the customary adjustments to the purchase price.

+ References

No definition available.

+ Details

Name:	brn_SignificantAcquisitionsAndDisposalsTimeLagForFinalDeterminationOfCustomaryAdjustmentsToThePurchasePrice
Namespace Prefix:	brn_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of real estate properties owned as of the balance sheet date.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfRealEstateProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

The value of all consideration given or received by the Entity in the significant acquisition or disposal.

+ References

No definition available.

+ Details

Name:	us-gaap_SignificantAcquisitionsAndDisposalsAcquisitionCostsOrSaleProceeds
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

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

- Details

Name:	brn_PhaseAxis=brn_PhaseOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	brn_PhaseAxis=brn_PhaseTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=brn_KaupulehuDevelopmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=brn_ResidentialParcelMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix:
Data Type:	na
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SUBSEQUENT EVENTS (Details) (USD $)	12 Months Ended		1 Months Ended	0 Months Ended
SUBSEQUENT EVENTS (Details) (USD $)	Sep. 30, 2014	Sep. 30, 2013	Oct. 31, 2014	Nov. 13, 2014
Kaupulehu Developments
Subsequent events
Percentage of sales payment received	$ 740,000	$ 300,000
Phase I \| Kaupulehu Developments
Subsequent events
Number of lots sold in Increment I	32
Phase II \| Kaupulehu Developments
Subsequent events
Number of lots sold in Increment I	3
Investment in land
Subsequent events
Number of residential parcels owned	2
Subsequent event \| Kaupulehu Developments
Subsequent events
Percentage of sales payment received			1,200,000
Subsequent event \| Oil and gas properties \| Progress area of Alberta
Subsequent events
Purchase or sales price				(526,000)
Period after closing of agreement for final determination of the customary adjustments to the purchase price				180 days
Subsequent event \| Phase I \| Kaupulehu Developments
Subsequent events
Number of lots sold in Increment I			6
Subsequent event \| Phase II \| Kaupulehu Developments
Subsequent events
Number of lots sold in Increment I			2
Subsequent event \| Investment in land
Subsequent events
Number of residential parcels sold			1
Purchase or sales price			1,250,000
Cash proceeds received (payments made)			$ 343,000
Period after purchase closing date mortgage is due			270 days