XML 76 R58.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Summary of Significant Accounting Policies - Additional Information (Details) |  |  | 1 Months Ended | 3 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | ---
Jan. 01, 2018 USD ($) | Jul. 05, 2011 patent | Nov. 30, 2016 USD ($) | Jul. 31, 2015 patent | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) Customer | Dec. 31, 2017 USD ($) | Dec. 31, 2017 USD ($) Segment | Dec. 31, 2017 USD ($) Reporting_Unit | Dec. 31, 2017 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) Customer | Dec. 31, 2015 USD ($)
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of inventory as a percentage of prior year purchases that can be returned by certain distributors |  |  |  |  |  |  |  |  |  |  | 3.00% |  |
Unprocessed adjustments recognized against gross accounts receivables |  |  |  |  |  |  |  |  |  | $ 35,700,000 |  | $ 23,300,000 |
Bad debt expense, net of recoveries |  |  |  |  |  |  |  |  |  | 0 |  | $ 1,500,000 | $ (1,800,000)
Accounts receivable recovered |  |  |  |  |  |  |  |  |  |  |  |  | 2,700,000
Number of customers with accounts receivable recovered | Customer |  |  |  |  |  | 1 |  |  |  |  |  | 1 |
Allowance for doubtful accounts |  |  |  |  | $ 7,800,000 | $ 8,100,000 | $ 7,800,000 | $ 7,800,000 | $ 7,800,000 | 7,800,000 | $ 7,800,000 | $ 8,100,000 |
Obsolescence and other reserves |  |  |  |  | 25,269,000 | 24,561,000 | 25,269,000 | 25,269,000 | $ 25,269,000 | 25,269,000 | 25,269,000 | 24,561,000 |
Number of reporting units used in qualitative assessment | Reporting_Unit |  |  |  |  |  |  |  |  | 7 |  |  |  |
Goodwill qualitative assessment |  |  |  |  | 547,200,000 |  | 547,200,000 | 547,200,000 | $ 547,200,000 | 547,200,000 | 547,200,000 |  |
Goodwill, portion related to reporting units |  |  |  |  | 931,100,000 |  | 931,100,000 | $ 931,100,000 | $ 931,100,000 | 931,100,000 | 931,100,000 |  |
Number of reportable segments |  |  |  |  |  |  |  | 4 | 5 |  |  |  |
Accrued rebates |  |  |  |  | 38,025,000 | 33,071,000 | $ 38,025,000 | $ 38,025,000 | $ 38,025,000 | 38,025,000 | $ 38,025,000 | 33,071,000 |
Royalty revenues |  |  |  |  |  | 10,300,000 |  |  |  |  |  |  |
Advertising costs |  |  |  |  |  |  |  |  |  | 25,000,000 |  | 27,200,000 | 27,500,000
Tax Cuts and Jobs Act of 2017, transition tax for accumulated foreign earnings, income tax expense |  |  |  |  | 29,100,000 |  |  |  |  | 29,100,000 |  |  |
Tax Cuts and Jobs Act of 2017, remeasurement of deferred tax assets and liabilities |  |  |  |  | 36,000,000 |  |  |  |  | 36,000,000 |  |  |
Tax Cuts and Jobs Act of 2017, valuation allowance against foreign tax credit carryforward |  |  |  |  | $ (35,300,000) |  |  |  |  | (35,300,000) |  |  |
Goodwill impairment |  |  |  |  |  |  |  |  |  | 0 |  | 0 | 0
Indefinite lived intangible asset impairment |  |  |  |  |  |  |  |  |  | 0 |  | 0 | 0
Amortizable intangible asset impairment |  |  |  |  |  |  |  |  |  | 0 |  | 0 | 0
Reportable Segment [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Royalty revenues |  |  |  |  |  |  |  |  |  | 0 |  | 5,554,000 | 0
Broadcast Solutions [Member] | Reportable Segment [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Royalty revenues |  |  |  |  |  |  |  |  |  | 0 |  | 5,554,000 | $ 0
Subsidiaries [Member] | Corning [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Patents allegedly infringed upon | patent |  | 2 |  |  |  |  |  |  |  |  |  |  |
Litigation settlement, amount |  |  | $ 61,300,000 |  |  |  |  |  |  |  |  |  |
Royalty revenues |  |  |  |  |  |  |  |  |  |  |  | 10,300,000 |
Number of patents found infringed upon | patent |  |  |  | 2 |  |  |  |  |  |  |  |  |
Subsidiaries [Member] | Corning [Member] | Reportable Segment [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Royalty revenues |  |  |  |  |  |  |  |  |  |  |  | 5,600,000 |
Subsidiaries [Member] | Corning [Member] | Broadcast Solutions [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Royalty revenues |  |  |  |  |  |  |  |  |  |  |  | 4,700,000 |
Hirschmann Jv [Member] | Discontinued Operations, Held-for-sale [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Equity method investment, realized Loss on disposal |  |  |  |  |  |  |  |  |  | $ 1,000,000 |  |  |
Equity method investments |  |  |  |  |  | $ 26,800,000 |  |  |  |  |  | $ 26,800,000 |
Hirschmann Jv [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Equity method investment, ownership percentage |  |  |  |  | 50.00% |  | 50.00% | 50.00% | 50.00% | 50.00% | 50.00% |  |
Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful life of related assets |  |  |  |  |  |  | 1 year |  |  |  |  |  |
Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful life of related assets |  |  |  |  |  |  | 25 years |  |  |  |  |  |
Buildings [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful life of related assets |  |  |  |  |  |  | P10Y |  |  |  |  |  |
Buildings [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful life of related assets |  |  |  |  |  |  | P40Y |  |  |  |  |  |
Machinery and Equipment [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful life of related assets |  |  |  |  |  |  | P5Y |  |  |  |  |  |
Machinery and Equipment [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful life of related assets |  |  |  |  |  |  | P12Y |  |  |  |  |  |
Computer Equipment and Software [Member] | Minimum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful life of related assets |  |  |  |  |  |  | P5Y |  |  |  |  |  |
Computer Equipment and Software [Member] | Maximum [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful life of related assets |  |  |  |  |  |  | P10Y |  |  |  |  |  |
Scenario, Forecast [Member] | Accounting Standards Update 2014-09 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Cumulative effect on retained earnings expected in next year | $ 2,600,000 |  |  |  |  |  |  |  |  |  |  |  |

X
- Definition Accrued sales rebates. + References No definition available. + Details
Name: | bdc_AccruedSalesRebates
Namespace Prefix: | bdc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of inventory as a percentage of prior year purchases that can be returned by certain distributors in accordance with contractual agreements. + References No definition available. + Details
Name: | bdc_AmountOfInventoryAsPercentageOfPriorYearPurchasesThatCanBeReturnedByCertainDistributors
Namespace Prefix: | bdc_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Goodwill, Portion Related To Reporting Units + References No definition available. + Details
Name: | bdc_GoodwillPortionRelatedToReportingUnits
Namespace Prefix: | bdc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of goodwill tested for impairment using the Qualitative Assessment approach. + References No definition available. + Details
Name: | bdc_GoodwillQualitativeAssessment
Namespace Prefix: | bdc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of customers with significant accounts receivable balance recovered. + References No definition available. + Details
Name: | bdc_NumberOfCustomersWithSignificantAccountsReceivableBalanceRecovered
Namespace Prefix: | bdc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of Reporting Units Used in Qualitative Assessment + References No definition available. + Details
Name: | bdc_NumberofReportingUnitsUsedinQualitativeAssessment
Namespace Prefix: | bdc_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Significant Accounting Policies [Line Items] + References No definition available. + Details
Name: | bdc_SignificantAccountingPoliciesLineItems
Namespace Prefix: | bdc_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tax Cuts And Jobs Act Of 2017, Remeasurement Of Deferred Tax Assets And Liabilities + References No definition available. + Details
Name: | bdc_TaxCutsAndJobsActOf2017RemeasurementOfDeferredTaxAssetsAndLiabilities
Namespace Prefix: | bdc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Tax Cuts And Jobs Act Of 2017, Transition Tax For Accumulated Foreign Earnings, Income Tax Expense (Benefit) + References No definition available. + Details
Name: | bdc_TaxCutsAndJobsActOf2017TransitionTaxForAccumulatedForeignEarningsIncomeTaxExpenseBenefit
Namespace Prefix: | bdc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Tax Cuts And Jobs Act Of 2017, Valuation Allowance Against Foreign Tax Credit Carryforward + References No definition available. + Details
Name: | bdc_TaxCutsAndJobsActOf2017ValuationAllowanceAgainstForeignTaxCreditCarryforward
Namespace Prefix: | bdc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Unprocessed adjustments recognized against accounts receivable. + References No definition available. + Details
Name: | bdc_UnprocessedAdjustmentsRecognizedAgainstAccountsReceivable
Namespace Prefix: | bdc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 720 -SubTopic 35 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6420018&loc=d3e36677-107848 + Details
Name: | us-gaap_AdvertisingExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.4) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524 + Details
Name: | us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of recoveries of receivables doubtful of collection that were previously charged off. + References No definition available. + Details
Name: | us-gaap_AllowanceForDoubtfulAccountsReceivableRecoveries
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of the cumulative effect on retained earnings net of related income tax effect. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=64853466&loc=d3e22663-107794 + Details
Name: | us-gaap_CumulativeEffectOnRetainedEarningsNetOfTax1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Amount of gain (loss) on sale or disposal of an equity method investment. + References No definition available. + Details
Name: | us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition This item represents the carrying amount on the entity's balance sheet of its investment in common stock of an equity method investee. This is not an indicator of the fair value of the investment, rather it is the initial cost adjusted for the entity's share of earnings and losses of the investee, adjusted for any distributions (dividends) and other than temporary impairment (OTTI) losses recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=66022249&loc=d3e33749-111570 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_EquityMethodInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_FiniteLivedIntangibleAssetUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of entity's patents that another entity has allegedly infringed. + References No definition available. + Details
Name: | us-gaap_GainContingencyPatentsAllegedlyInfringedUponNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of entity's patents that another entity was found to have infringed. + References No definition available. + Details
Name: | us-gaap_GainContingencyPatentsFoundInfringedUponNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13854-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13777-109266 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 + Details
Name: | us-gaap_GoodwillImpairmentLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of impairment loss recognized in the period resulting from the write-down of the carrying amount of an intangible asset (excluding goodwill) to fair value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16373-109275 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 + Details
Name: | us-gaap_ImpairmentOfIntangibleAssetsExcludingGoodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16373-109275 + Details
Name: | us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of valuation reserve for inventory. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 330 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SAB TOPIC 5.BB) -URI http://asc.fasb.org/extlink&oid=27011343&loc=d3e100047-122729 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.6(a)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e24092-122690 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 330 -SubTopic 10 -Section 35 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=68049868&loc=d3e3927-108312 + Details
Name: | us-gaap_InventoryValuationReserves
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount awarded from other party in judgment or settlement of litigation. + References No definition available. + Details
Name: | us-gaap_LitigationSettlementAmountAwardedFromOtherParty
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. + References No definition available. + Details
Name: | us-gaap_NumberOfReportableSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Describes the periods of time over which an entity anticipates to receive utility from its property, plant and equipment (that is, the periods of time over which an entity allocates the initial cost of its property, plant and equipment). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=84158767&loc=d3e18780-107790 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 360 -SubTopic 10 -Section 35 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=68071081&loc=d3e1205-110223 + Details
Name: | us-gaap_PropertyPlantAndEquipmentEstimatedUsefulLives
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of expense related to write-down of receivables to the amount expected to be collected. Includes, but is not limited to, accounts receivable and notes receivable. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=82913815&loc=SL49130534-203044 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.5) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3602-108585 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 606 -SubTopic 10 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=82913847&loc=SL49130543-203045 + Details
Name: | us-gaap_ProvisionForDoubtfulAccounts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Revenue earned during the period from the leasing or otherwise lending to a third party the entity's rights or title to certain property. Royalty revenue is derived from a percentage or stated amount of sales proceeds or revenue generated by the third party using the entity's property. Examples of property from which royalties may be derived include patents and oil and mineral rights. + 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(e)) -URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688 + Details
Name: | us-gaap_RoyaltyRevenue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=bdc_BroadcastSolutionsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConsolidatedEntitiesAxis=us-gaap_SubsidiariesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LitigationCaseAxis=bdc_CorningMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=bdc_HirschmannJvMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DisposalGroupClassificationAxis=us-gaap_DiscontinuedOperationsHeldforsaleMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | invest_InvestmentAxis=bdc_HirschmannJvMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_BuildingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=us-gaap_MachineryAndEquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=bdc_ComputerEquipmentAndSoftwareMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_ScenarioForecastMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=us-gaap_AccountingStandardsUpdate201409Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |