v2.3.0.15

Financing Liability for Construction in Progress (Details) (USD $) In Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2011	Dec. 31, 2010	Dec. 31, 2009
Financing Liability for Construction in Progress (Textual) [Abstract]
Structural leasehold improvement costs incurred during construction		$ 18.9
Construction costs reimbursed by the landlord	18.8
Fair value of the building capitalized			6.9
Increased liability due to additional structural leasehold improvements		18.9
Increased liability due to land lease expense		0.2
Increased liability due to capitalized interest expense		$ 0.2

X

- Definition

Construction costs reimbursed by landlord.

+ Details

Name:	hlit_ConstructionCostsReimbursedByLandlord
Namespace Prefix:	hlit
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Financing liability for construction in progress.

+ Details

Name:	hlit_FinancingLiabilityForConstructionInProgressTextualAbstract
Namespace Prefix:	hlit
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Increased liability due to additional structural leasehold improvements.

+ Details

Name:	hlit_IncreasedLiabilityDueToAdditionalStructuralLeaseholdImprovements
Namespace Prefix:	hlit
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Increased liability due to capitalized interest expense.

+ Details

Name:	hlit_IncreasedLiabilityDueToCapitalizedInterestExpense
Namespace Prefix:	hlit
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Increased liability due to land lease expense.

+ Details

Name:	hlit_IncreasedLiabilityDueToLandLeaseExpense
Namespace Prefix:	hlit
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Structural leasehold improvement costs incurred during construction.

+ Details

Name:	hlit_StructuralLeaseholdImprovementCostsIncurredDuringConstruction
Namespace Prefix:	hlit
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software, net of accumulated depreciation.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 33

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_PropertyPlantAndEquipmentFairValueDisclosure
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant