Operating Segments - Reconciliation of Total Reportable Segments' Revenues and EBITDA to Consolidated Revenues and Consolidated Income (Loss) from Continuing Operations Before Taxes (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 29, 2015	Mar. 30, 2014
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Consolidated Revenues	$ 546,957us-gaap_SalesRevenueGoodsNet	$ 487,690us-gaap_SalesRevenueGoodsNet
Income from equity method investment	768	954
Amortization of intangibles	(26,504)us-gaap_AmortizationOfIntangibleAssets	(11,741)us-gaap_AmortizationOfIntangibleAssets
Severance, restructuring, and acquisition integration costs (2)	(14,483)us-gaap_RestructuringCharges	(2,295)us-gaap_RestructuringCharges
Depreciation expense	(11,500)us-gaap_Depreciation	(9,500)us-gaap_Depreciation
Consolidated operating income	4,898us-gaap_OperatingIncomeLoss	49,511us-gaap_OperatingIncomeLoss
Interest expense	(23,926)us-gaap_InterestExpense	(18,820)us-gaap_InterestExpense
Interest income	80us-gaap_InvestmentIncomeInterest	150us-gaap_InvestmentIncomeInterest
Consolidated income (loss) from continuing operations before taxes	(18,948)	30,841
Reportable Segment [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Consolidated Revenues	569,451	488,307
Deferred revenue adjustments	(22,494)	(617)
Total Segment EBITDA	88,274	73,616
Amortization of intangibles	(26,504)	(11,741)
Deferred gross profit adjustments	(21,658)	(450)
Severance, restructuring, and acquisition integration costs (2)	(14,483)	(2,295)
Depreciation expense	(11,541)	(9,497)
Consolidated operating income	(9,422)
Eliminations [Member]
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Consolidated operating income	$ (536)	$ (1,076)

Operating Segments - Reconciliation of Total Reportable Segments' Revenues and EBITDA to Consolidated Revenues and Consolidated Income (Loss) from Continuing Operations Before Taxes (Detail) (USD $)
In Thousands, unless otherwise specified

3 Months Ended

Mar. 29, 2015

Mar. 30, 2014

Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]

Consolidated Revenues

$ 546,957us-gaap_SalesRevenueGoodsNet

$ 487,690us-gaap_SalesRevenueGoodsNet

Income from equity method investment

768us-gaap_IncomeLossFromEquityMethodInvestments

954us-gaap_IncomeLossFromEquityMethodInvestments

Amortization of intangibles

(26,504)us-gaap_AmortizationOfIntangibleAssets

(11,741)us-gaap_AmortizationOfIntangibleAssets

Severance, restructuring, and acquisition integration costs (2)

(14,483)us-gaap_RestructuringCharges

(2,295)us-gaap_RestructuringCharges

Depreciation expense

(11,500)us-gaap_Depreciation

(9,500)us-gaap_Depreciation

Consolidated operating income

4,898us-gaap_OperatingIncomeLoss

49,511us-gaap_OperatingIncomeLoss

Interest expense

(23,926)us-gaap_InterestExpense

(18,820)us-gaap_InterestExpense

Interest income

80us-gaap_InvestmentIncomeInterest

150us-gaap_InvestmentIncomeInterest

Consolidated income (loss) from continuing operations before taxes

(18,948)us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

30,841us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

Reportable Segment [Member]

Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]

Consolidated Revenues

569,451us-gaap_SalesRevenueGoodsNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember

488,307us-gaap_SalesRevenueGoodsNet
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember

Deferred revenue adjustments

(22,494)bdc_DeferredRevenueAdjustments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember

(617)bdc_DeferredRevenueAdjustments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember

Total Segment EBITDA

88,274bdc_EarningsBeforeInterestTaxesDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember

73,616bdc_EarningsBeforeInterestTaxesDepreciationAndAmortization
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember

Amortization of intangibles

(26,504)us-gaap_AmortizationOfIntangibleAssets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember

(11,741)us-gaap_AmortizationOfIntangibleAssets
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember

Deferred gross profit adjustments

(21,658)bdc_DeferredGrossProfitAdjustments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember

(450)bdc_DeferredGrossProfitAdjustments
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember

Severance, restructuring, and acquisition integration costs (2)

(14,483)us-gaap_RestructuringCharges
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember

(2,295)us-gaap_RestructuringCharges
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember

Depreciation expense

(11,541)us-gaap_Depreciation
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember

(9,497)us-gaap_Depreciation
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember

Consolidated operating income

(9,422)us-gaap_OperatingIncomeLoss
/ us-gaap_ConsolidationItemsAxis
= us-gaap_OperatingSegmentsMember

Eliminations [Member]

Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]

Consolidated operating income

$ (536)us-gaap_OperatingIncomeLoss
/ us-gaap_ConsolidationItemsAxis
= us-gaap_IntersegmentEliminationMember

$ (1,076)us-gaap_OperatingIncomeLoss
/ us-gaap_ConsolidationItemsAxis
= us-gaap_IntersegmentEliminationMember

- Definition

Amount of gross profit adjustments related to the reduction in fair value of acquired deferred revenue as a result of purchase accounting.

+ References

No definition available.

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- Definition

Amount of any adjustments related to the reduction in fair value of acquired deferred revenue as a result of purchase accounting.

+ References

No definition available.

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- Definition

Earnings before interest, taxes, depreciation, amortization, restructuring charges, effects of purchase accounting, and other costs.

+ References

No definition available.

+ Details

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- Definition

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

+ References

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- Definition

The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

+ References

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- Definition

This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 20

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 10

-Article 5

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- Definition

This item represents the entity's proportionate share for the period of the net income (loss) of its investee (such as unconsolidated subsidiaries and joint ventures) to which the equity method of accounting is applied. This item includes income or expense related to stock-based compensation based on the investor's grant of stock to employees of an equity method investee.

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-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

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-Number 210

-Section 04

-Paragraph 11

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- Definition

Amount of the cost of borrowed funds accounted for as interest expense.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 20

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-Section 04

-Paragraph 9

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- Definition

Amount before accretion (amortization) of purchase discount (premium) of interest income on nonoperating securities.

+ References

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

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-Topic 225

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-Paragraph 2

-Subparagraph (SX 210.5-03.7(b))

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- Definition

The net result for the period of deducting operating expenses from operating revenues.

+ References

No definition available.

+ Details

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- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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-Name Staff Accounting Bulletin (SAB)

-Number Topic 5

-Section P

-Subsection 3, 4

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Aggregate revenue during the period from the sale of goods in the normal course of business, after deducting returns, allowances and discounts.

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-Name Regulation S-X (SX)

-Number 210

-Section 03

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