XML 45 R35.htm IDEA: XBRL DOCUMENT
v2.4.0.8

BUSINESS SEGMENT INFORMATION (Details) (USD $) | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2013 Industry Segment | Sep. 30, 2012 Segment Industry | Sep. 30, 2013 Industry Segment | Sep. 30, 2012 Industry Segment
BUSINESS SEGMENT INFORMATION [Abstract] |  |  |  |
Number of industry in which entity operates | 1 | 1 | 1 | 1
Number of reportable operating segments | 3 | 3 | 3 | 3
Total segment sales [Abstract] |  |  |  |
Total segment sales | $ 113,188,000 | $ 90,591,000 | $ 292,187,000 | $ 256,430,000
Reconciling item [Abstract] |  |  |  |
Intersegment sales | (12,024,000) | (14,532,000) | (34,014,000) | (41,588,000)
Net Sales | 101,164,000 | 76,059,000 | 258,173,000 | 214,842,000
Income from operations [Abstract] |  |  |  |
Income (loss) from operations | 8,328,000 | 880,000 | 9,430,000 | 4,642,000
North America [Member] |  |  |  |
Total segment sales [Abstract] |  |  |  |
Total segment sales | 34,273,000 | 34,370,000 | 95,796,000 | 106,349,000
Income from operations [Abstract] |  |  |  |
Income (loss) from operations | (96,000) | (189,000) | (3,591,000) | 4,074,000
Combined revenue from acquired companies | 800,000 |  | 800,000 |
Asia [Member] |  |  |  |
Total segment sales [Abstract] |  |  |  |
Total segment sales | 69,602,000 | 47,238,000 | 166,362,000 | 125,881,000
Income from operations [Abstract] |  |  |  |
Income (loss) from operations | 8,400,000 | 1,048,000 | 12,377,000 | 8,000
Combined revenue from acquired companies | 25,600,000 |  | 47,800,000 |
Combined income from operations from acquired companies | 5,000,000 |  | 9,500,000 |
Europe [Member] |  |  |  |
Total segment sales [Abstract] |  |  |  |
Total segment sales | 9,313,000 | 8,983,000 | 30,029,000 | 24,200,000
Income from operations [Abstract] |  |  |  |
Income (loss) from operations | 24,000 | 21,000 | 644,000 | 560,000
Combined revenue from acquired companies | 1,800,000 | 900,000 | 7,700,000 | 900,000
Combined income from operations from acquired companies | $ 100,000 | $ 100,000 | $ 1,300,000 | $ 100,000

X
- Definition Number of industry in which entity operates with its reportable operating segments. + References No definition available. + Details
Name: | belfb_NumberOfIndustryInWhichEntityOperates
Namespace Prefix: | belfb_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of reportable operating segments of the entity. + References No definition available. + Details
Name: | belfb_NumberOfReportableOperatingSegments
Namespace Prefix: | belfb_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | belfb_ReconcilingItemAbstract
Namespace Prefix: | belfb_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition This element represents the amount of earnings or loss of the acquiree since the acquisition date included in the consolidated income statement for the reporting period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1) -URI http://asc.fasb.org/extlink&oid=7659399&loc=d3e1392-128463 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 68 -Subparagraph r(1) -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
Name: | us-gaap_BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition This element represents the amount of revenue of the acquiree since the acquisition date included in the consolidated income statement for the reporting period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1) -URI http://asc.fasb.org/extlink&oid=7659399&loc=d3e1392-128463 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 68 -Subparagraph r(1) -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
Name: | us-gaap_BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The net result for the period of deducting operating expenses from operating revenues. + References No definition available. + Details
Name: | us-gaap_OperatingIncomeLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_ReconciliationOfOperatingProfitLossFromSegmentsToConsolidatedAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of revenue from transactions with other operating segments of the same entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 131 -Paragraph 27 -Subparagraph b -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
Name: | us-gaap_RevenuesFromTransactionsWithOtherOperatingSegmentsOfSameEntity
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Aggregate revenue during the period from the sale of goods in the normal course of business, after deducting returns, allowances and discounts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1(a)) -URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Article 5 + Details
Name: | us-gaap_SalesRevenueGoodsNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_SegmentReportingAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of total revenue for the reportable segments, including revenue from external customers, transactions with other operating segments of the same entity, and (gross) interest revenue. All considered to be "operating revenue" for purposes of the taxonomy. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -Subparagraph (a),(b),(c) -URI http://asc.fasb.org/extlink&oid=6534315&loc=d3e8736-108599 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 131 -Paragraph 27 -Subparagraph a, b, c -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
Name: | us-gaap_SegmentReportingInformationRevenue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_SegmentReportingInformationRevenueAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration