INCENTIVE COMPENSATION PLAN (Details) (USD $)	12 Months Ended
Sep. 30, 2012	Sep. 30, 2011
INCENTIVE COMPENSATION PLAN
Costs recognized pursuant to plan	$ 0	$ 41,000
Amounts accrued under the plan	$ 394,000	$ 681,000

The carrying amount of the liability as of the balance sheet date under an incentive compensation arrangement.

No definition available.

Name:	brn_IncentiveCompensationPlanRecordedLiability
Namespace Prefix:	brn_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant