Credit Facilities - Additional Information (Detail) - JPMorgan Chase [Member] - USD ($)	6 Months Ended
	Jul. 03, 2015	Dec. 22, 2014
Commercial Letters of Credit [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Commitment Fee Percentage	0.75%
Line of Credit Facility, Commitment Fee Amount	$ 100
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Percentage of Equity Interest Pledged as Collateral for Letter of Credit	66.67%
Line of Credit Facility, Current Borrowing Capacity		$ 20,000,000
Line of Credit Facility, Remaining Borrowing Capacity	$ 19,500,000
Borrowings under bank line of credit facility	$ 0
Credit facility collateral	Obligations under the Credit Agreement are secured only by a pledge of 66 2/3% of the Company’s equity interests in its foreign subsidiary, Harmonic International AG. Additionally, to the extent that the Company in the future forms any direct or indirect, domestic, material subsidiaries, those subsidiaries will be required to provide a guaranty of the Company’s obligations under the Credit Agreement.
Line of Credit Facility, Threshold Consecutive Business Days	5 days
Debt Instrument, Fee Amount	$ 50,000
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage	0.25%
Line of Credit, Covenant, Consolidated Cash and Marketable Securities Minimum	$ 35,000,000
Line of Credit Covenant, EBITDA, Minimum	20,000,000
Revolving Credit Facility [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Consolidated Cash Threshold	30,000,000
Standby letters of credit [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Current Borrowing Capacity		$ 10,000,000
Line of Credit Facility, Remaining Borrowing Capacity	$ 500,000
Line of Credit Facility, Commitment Fee Percentage	1.75%
LIBOR [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
LIBOR rate duration	LIBOR
Adjusted LIBOR Rate, Variable Rate, Period End Month One	1 month
Adjusted LIBOR Rate, Variable Rate, Period End Month Two	2 months
Adjusted LIBOR Rate, Variable Rate, Period End Month Three	3 months
LIBOR [Member] | Revolving Credit Facility [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Line of Credit LIBOR margin	2.50%
Adjusted LIBOR Rate Applicable Margin Rate [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit LIBOR margin	1.75%
Prime Rate [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
LIBOR rate duration	prime
Adjusted Prime Rate Applicable Margin Rate [Member] | Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of Credit LIBOR margin	(1.30%)