Basis of Presentation and Significant Accounting Policies - Additional Information (Detail) (HFC business [Member], USD $) In Thousands, unless otherwise specified	1 Months Ended	9 Months Ended
Mar. 05, 2013	Sep. 27, 2013
HFC business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Business sold for cash agreed by the company	$ 46,000	$ 46,000

Discontinued Operation Gross Cash Proceeds Received From Sale Of Business

No definition available.

Name:	hlit_DiscontinuedOperationGrossCashProceedsReceivedFromSaleOfBusiness
Namespace Prefix:	hlit_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration