Fair Value (Details Textual) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 30, 2012 Securities
Fair Value (Textual) [Abstract]
Nonrecurring fair value measurements of assets and liabilities subsequent to initial recognition	$ 0
Individual available for sale securities in a material unrealized loss position	0

Nonrecurring fair value measurements of assets and liabilities subsequent to initial recognition.

No definition available.

Name:	hlit_NonrecurringFairValueMeasurementsOfAssetsAndLiabilitiesSubsequentToInitialRecognition
Namespace Prefix:	hlit_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration