v2.4.1.9
Investments (Details 2) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Investments [Line Items]    
Total operating expenses $ 300us-gaap_OperatingExpenses $ 708us-gaap_OperatingExpenses
Other expense (734)us-gaap_OtherNonoperatingIncomeExpense (1,678)us-gaap_OtherNonoperatingIncomeExpense
Provision (benefit) for income taxes 0us-gaap_IncomeTaxExpenseBenefit 0us-gaap_IncomeTaxExpenseBenefit
Net Income (989)us-gaap_NetIncomeLoss (2,343)us-gaap_NetIncomeLoss
Interlink Electronics [Member]    
Investments [Line Items]    
Net revenues 10,278us-gaap_SalesRevenueNet
/ dei_LegalEntityAxis
= bkfg_InterlinkElectronicsMember
 
Cost of goods sold 5,200us-gaap_CostOfGoodsSold
/ dei_LegalEntityAxis
= bkfg_InterlinkElectronicsMember
 
Gross profit 5,078us-gaap_GrossProfit
/ dei_LegalEntityAxis
= bkfg_InterlinkElectronicsMember
 
Total operating expenses 3,530us-gaap_OperatingExpenses
/ dei_LegalEntityAxis
= bkfg_InterlinkElectronicsMember
 
Income from operations 1,548us-gaap_OperatingIncomeLoss
/ dei_LegalEntityAxis
= bkfg_InterlinkElectronicsMember
 
Other expense (14)us-gaap_OtherNonoperatingIncomeExpense
/ dei_LegalEntityAxis
= bkfg_InterlinkElectronicsMember
 
Income from continuing operations before income taxes 1,534us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest
/ dei_LegalEntityAxis
= bkfg_InterlinkElectronicsMember
 
Income from discontinued operations 34us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax
/ dei_LegalEntityAxis
= bkfg_InterlinkElectronicsMember
 
Provision (benefit) for income taxes (13)us-gaap_IncomeTaxExpenseBenefit
/ dei_LegalEntityAxis
= bkfg_InterlinkElectronicsMember
 
Net Income $ 1,555us-gaap_NetIncomeLoss
/ dei_LegalEntityAxis
= bkfg_InterlinkElectronicsMember