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v2.4.1.9

Debt (Details) (USD $) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2014 | Dec. 31, 2013 | Jul. 31, 2014
Line of Credit Facility [Line Items] |  |  |
Additional borrowings |  |  | $ 90,000,000 us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases
Scheduled principal payments [Abstract] |  |  |
2015 | 13,438,000 us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths |  |
2016 | 16,125,000 us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo |  |
2017 | 18,812,000 us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree |  |
2018 | 24,188,000 us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour |  |
2019 | 160,062,000 us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive |  |
Total long-term debt | 232,625,000 us-gaap_LongTermDebt |  |
Less: Current maturities of long-term debt | (13,438,000)us-gaap_LongTermDebtCurrent | 0 us-gaap_LongTermDebtCurrent |
Noncurrent portion of long-term debt | 219,187,000 us-gaap_LongTermDebtNoncurrent | 0 us-gaap_LongTermDebtNoncurrent |
New Secured Credit Agreement [Member] |  |  |
Line of Credit Facility [Line Items] |  |  |
Additional borrowings | 100,000,000 us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember |  |
Percentage of capital stock of foreign subsidiaries given as collateralized security to line of credit (in hundredths) | 65.00%belfb_PercentageOfCapitalStockOfForeignSubsidiariesGivenAsCollateralizedSecurityToLineOfCredit / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember |  |
Basis spread on variable rate (in hundredths) | 2.75%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember |  |
Interest on borrowings outstanding (in hundredths) | 2.94%us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember |  |
Effective LIBOR rate (in hundredths) | 0.19%belfb_EffectiveLibor / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember |  |
Line of credit, current borrowing capacity | 27,000,000 us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember |  |
Available to borrow without violating our Leverage Ratio covenant | 16,200,000 belfb_AvailableToBorrowWithoutViolatingOurLeverageRatioCovenant / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember |  |
Deferred financing costs | 5,800,000 belfb_DeferredFinancingCosts / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember |  |
Deferred financing costs amortization period | 5 years |  |
Interest expense incurred | 4,000,000 us-gaap_InterestExpenseDebt / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember |  |
New Secured Credit Agreement [Member] | LIBOR [Member] |  |  |
Line of Credit Facility [Line Items] |  |  |
Basis spread on variable rate (in hundredths) | 1.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |
New Secured Credit Agreement [Member] | Federal Funds Rate [Member] |  |  |
Line of Credit Facility [Line Items] |  |  |
Basis spread on variable rate (in hundredths) | 0.50%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember / us-gaap_VariableRateAxis = us-gaap_FederalFundsEffectiveSwapRateMember |  |
Line of Credit [Member] |  |  |
Line of Credit Facility [Line Items] |  |  |
Available line of credit |  | 30,000,000 us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_LineOfCreditMember |
Interest on borrowings outstanding (in hundredths) |  | 1.40%us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd / us-gaap_CreditFacilityAxis = us-gaap_LineOfCreditMember |
Line of credit, current borrowing capacity |  | 18,000,000 us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_LineOfCreditMember |
Line of credit, amount outstanding |  | 12,000,000 us-gaap_LineOfCredit / us-gaap_CreditFacilityAxis = us-gaap_LineOfCreditMember |
Line of credit facility, expiration date |  | Oct. 14, 2016 |
Interest expense incurred | 100,000 us-gaap_InterestExpenseDebt / us-gaap_CreditFacilityAxis = us-gaap_LineOfCreditMember | 200,000 us-gaap_InterestExpenseDebt / us-gaap_CreditFacilityAxis = us-gaap_LineOfCreditMember |
Repayments of line of credit | 12,000,000 us-gaap_RepaymentsOfLinesOfCredit / us-gaap_CreditFacilityAxis = us-gaap_LineOfCreditMember |  |
Revolving Credit Facility [Member] | New Secured Credit Agreement [Member] |  |  |
Line of Credit Facility [Line Items] |  |  |
Available line of credit | 50,000,000 us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember |  |
Additional borrowings |  |  | 20,000,000 us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember
Line of credit, amount outstanding | 23,000,000 us-gaap_LineOfCredit / us-gaap_CreditFacilityAxis = us-gaap_RevolvingCreditFacilityMember / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember |  |
Term Loan [Member] | New Secured Credit Agreement [Member] |  |  |
Line of Credit Facility [Line Items] |  |  |
Available line of credit | 145,000,000 us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis = belfb_TermLoanMember / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember |  |
Line of credit, amount outstanding | 145,000,000 us-gaap_LineOfCredit / us-gaap_CreditFacilityAxis = belfb_TermLoanMember / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember |  |
Delayed Draw Term Loan [Member] | New Secured Credit Agreement [Member] |  |  |
Line of Credit Facility [Line Items] |  |  |
Available line of credit | 70,000,000 us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity / us-gaap_CreditFacilityAxis = belfb_DelayedDrawTermLoanMember / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember |  |
Additional borrowings |  |  | 70,000,000 us-gaap_LineOfCreditFacilityCapacityAvailableForSpecificPurposeOtherThanForTradePurchases / us-gaap_CreditFacilityAxis = belfb_DelayedDrawTermLoanMember / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember
Line of credit, amount outstanding | $ 70,000,000 us-gaap_LineOfCredit / us-gaap_CreditFacilityAxis = belfb_DelayedDrawTermLoanMember / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember |  |
Minimum [Member] | New Secured Credit Agreement [Member] | LIBOR [Member] |  |  |
Line of Credit Facility [Line Items] |  |  |
Basis spread on variable rate (in hundredths) | 1.75%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |
Minimum [Member] | New Secured Credit Agreement [Member] | Alternate Base Rate [Member] |  |  |
Line of Credit Facility [Line Items] |  |  |
Basis spread on variable rate (in hundredths) | 0.75%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember / us-gaap_RangeAxis = us-gaap_MinimumMember / us-gaap_VariableRateAxis = us-gaap_BaseRateMember |  |
Minimum [Member] | Line of Credit [Member] |  |  |
Line of Credit Facility [Line Items] |  |  |
Basis spread on variable rate (in hundredths) |  | 1.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_CreditFacilityAxis = us-gaap_LineOfCreditMember / us-gaap_RangeAxis = us-gaap_MinimumMember |
Maximum [Member] | New Secured Credit Agreement [Member] | LIBOR [Member] |  |  |
Line of Credit Facility [Line Items] |  |  |
Basis spread on variable rate (in hundredths) | 3.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_VariableRateAxis = us-gaap_LondonInterbankOfferedRateLIBORMember |  |
Maximum [Member] | New Secured Credit Agreement [Member] | Alternate Base Rate [Member] |  |  |
Line of Credit Facility [Line Items] |  |  |
Basis spread on variable rate (in hundredths) | 2.00%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_LineOfCreditFacilityAxis = belfb_NewSecuredCreditAgreementMember / us-gaap_RangeAxis = us-gaap_MaximumMember / us-gaap_VariableRateAxis = us-gaap_BaseRateMember |  |
Maximum [Member] | Line of Credit [Member] |  |  |
Line of Credit Facility [Line Items] |  |  |
Basis spread on variable rate (in hundredths) |  | 1.50%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1 / us-gaap_CreditFacilityAxis = us-gaap_LineOfCreditMember / us-gaap_RangeAxis = us-gaap_MaximumMember |

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- Definition Represents amount available to borrow without violating Leverage Ratio covenant on balance sheet date. + References No definition available. + Details
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- Definition Refers to percentage of issued and outstanding shares of the capital stock of foreign subsidiaries given as collateralized security to line of credit. + References No definition available. + Details
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- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.16) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19, 20, 22 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.16) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 + Details
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