Name:	brn_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfExpectedLongTermReturnOnAssetsIncreaseDecrease
Namespace Prefix:	brn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

The increase (decrease) in pension expense that would occur if the expected return on plan assets was decreased (increased) by 50 basis points.

No definition available.

Name:	brn_DefinedBenefitPlanIncreaseDecreaseFromExpectedReturnOnPlanAssets
Namespace Prefix:	brn_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Investments Held for Sale [Abstract]

No definition available.

Name:	brn_InvestmentsHeldforSaleAbstract
Namespace Prefix:	brn_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Represents the number of joint ventures owned by the entity.

No definition available.

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

Represents the percentage of ownership interest in affiliated companies required to account investments under equity method investments.

No definition available.

Name:	brn_OwnershipInterestInAffiliatedCompaniesRequiredToAccountInvestmentsUnderEquityMethodInvestments
Namespace Prefix:	brn_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

Name:	brn_PrinciplesOfConsolidationAbstract
Namespace Prefix:	brn_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

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

- References

No definition available.

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

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

No definition available.

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

Percentage of subsidiary's or equity method investee's stock owned by parent immediately after all stock transactions.

No definition available.

Name:	us-gaap_SubsidiaryOrEquityMethodInvesteeCumulativePercentageOwnershipAfterAllTransactions
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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

Name:	dei_LegalEntityAxis=brn_KDKona2013LLLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	dei_LegalEntityAxis=brn_Kaupulehu2007LLLPMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: