Subsequent Events - Additional Information (Detail) (Subsequent Event [Member], USD $) In Millions, unless otherwise specified	1 Months Ended
Feb. 28, 2014
Subsequent Event [Member]
Subsequent Event [Line Items]
Cost of binding offer to purchase Grass Valley	$ 220

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer for a binding purchase offer.

No definition available.

Name:	bdc_BusinessCombinationBindingPurchaseOfferConsiderationOffered
Namespace Prefix:	bdc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration