Name:	bdc_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsLessThanPlanAssetsAggregateAccumulatedBenefitObligation
Namespace Prefix:	bdc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Defined benefit plan pension plans with accumulated benefit obligations less than plan assets aggregate benefit obligation.

No definition available.

Name:	bdc_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsLessThanPlanAssetsAggregateBenefitObligation
Namespace Prefix:	bdc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Defined benefit plan pension plans with accumulated benefit obligations less than plan assets aggregate fair value of plan assets.

No definition available.

Name:	bdc_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsLessThanPlanAssetsAggregateFairValueOfPlanAssets
Namespace Prefix:	bdc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Defined Benefit Plan Target Allocation Percentage Of Asset Equity Securities

No definition available.

Name:	bdc_DefinedBenefitPlanTargetAllocationPercentageOfAssetEquitySecurities
Namespace Prefix:	bdc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Defined Benefit Plan Target Allocation Percentage Of Assets Debt Securities And Cash

No definition available.

Name:	bdc_DefinedBenefitPlanTargetAllocationPercentageOfAssetsDebtSecuritiesAndCash
Namespace Prefix:	bdc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Defined Benefit Plan Target Allocation Percentage Of Assets Debt Securities Range Maximum1

No definition available.

Name:	bdc_DefinedBenefitPlanTargetAllocationPercentageOfAssetsDebtSecuritiesRangeMaximum1
Namespace Prefix:	bdc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Defined Benefit Plan Target Allocation Percentage Of Assets Debt Securities Range Minimum 1

No definition available.

Name:	bdc_DefinedBenefitPlanTargetAllocationPercentageOfAssetsDebtSecuritiesRangeMinimum1
Namespace Prefix:	bdc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Defined Benefit Plan Target Allocation Percentage Of Assets Equity Securities Range Maximum 1

No definition available.

Name:	bdc_DefinedBenefitPlanTargetAllocationPercentageOfAssetsEquitySecuritiesRangeMaximum1
Namespace Prefix:	bdc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Defined Benefit Plan Target Allocation Percentage Of Assets Equity Securities Range Minimum 1

No definition available.

Name:	bdc_DefinedBenefitPlanTargetAllocationPercentageOfAssetsEquitySecuritiesRangeMinimum1
Namespace Prefix:	bdc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

For defined benefit pension plans, the actuarial present value of benefits (whether vested or nonvested) attributed by the pension benefit formula to employee service rendered before a specified date and based on employee service and compensation (if applicable) before that date. The accumulated benefit obligation differs from the projected benefit obligation in that it includes no assumption about future compensation levels. For plans with flat-benefit or nonpay-related pension benefit formulas, the accumulated benefit obligation and the projected benefit obligation are the same.

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Accumulated Benefit Obligation

-URI http://asc.fasb.org/extlink&oid=6503844

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Name:	us-gaap_DefinedBenefitPlanDisclosureLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

If aggregate disclosures are presented, the aggregate pension accumulated benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 55

-Paragraph 17

-URI http://asc.fasb.org/extlink&oid=34716465&loc=d3e4179-114921

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e2417-114920

Name:	us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

If aggregate disclosures are presented, the aggregate fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

Name:	us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

If aggregate disclosures are presented, the aggregate projected benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

Name:	us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Amount of employer's best estimate of contributions expected to be paid to the plan during the next fiscal year beginning after the date of the latest statement of financial position.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=35743120&loc=d3e1928-114920

Name:	us-gaap_DefinedBenefitPlansEstimatedFutureEmployerContributionsInNextFiscalYear
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The amount of the cost recognized during the period for defined contribution plans.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 70

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942

Name:	us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Name:	us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis=us-gaap_OtherPensionPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

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