Restructuring and Related Charges - Additional Information (Detail) $ in Thousands	3 Months Ended		12 Months Ended
	Apr. 01, 2016 USD ($) Employee	Apr. 03, 2015 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) Employee	Dec. 31, 2014 USD ($)	Jan. 04, 2016 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	$ 2,583	$ 44
Anticipated Synergies from Restructuring Exit Plan	20,000
Restructuring and Related Cost, Incurred Cost	2,612	$ 44
Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 2,648
Number of positions eliminated | Employee	13
Harmonic Two Thousand And Fifteen Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges				$ 2,200	$ 1,500
Number of positions eliminated | Employee				56
Facility Closing [Member] | Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Fair Value of Excess Facility Restructuring						$ 2,500
Deferred Rent Credit						$ 1,100
Restructuring charges	$ 1,390
Employee Severance [Member] | Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	1,012
Other Restructuring [Member] | Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges	246
TVN [Member]
Restructuring Cost and Reserve [Line Items]
Business Combination, Acquisition Related Costs	3,096
TVN [Member] | Operating Expense [Member]
Restructuring Cost and Reserve [Line Items]
Business Combination, Acquisition Related Costs	$ 3,038
Scenario, Forecast [Member] | TVN [Member] | Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Costs			$ 20,000