Restructuring and Related Charges - Additional Information (Detail) $ in Thousands		1 Months Ended	3 Months Ended			6 Months Ended		12 Months Ended	18 Months Ended
		Jan. 31, 2016 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2016 USD ($) Employees	Jul. 01, 2016 USD ($)	Jun. 30, 2017 USD ($) Employee	Jul. 01, 2016 USD ($)	Dec. 31, 2016 USD ($) Employees	Jun. 30, 2017 USD ($)	Jan. 04, 2016 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost			$ 1,055		$ 1,909	$ 2,842	$ 4,492
Adjustments to restructuring provisions			777		1,903	2,056	4,515
Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost								$ 20,000
Charges for 2016 Harmonic Restructuring Plan						2,798
Adjustments to restructuring provisions						44
Facility Closing [Member] | Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost								2,200
Charges for 2016 Harmonic Restructuring Plan						48
Adjustments to restructuring provisions
Employee Severance And Benefit Arrangements [Member] | Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost								$ 17,800
Number of positions eliminated | Employees								118
Employee Severance [Member] | Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Charges for 2016 Harmonic Restructuring Plan	[1]					973
Adjustments to restructuring provisions	[1]					44
TVN Voluntary Departure Plan [Member] | Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Charges for 2016 Harmonic Restructuring Plan	[2]					1,777
Adjustments to restructuring provisions	[2]
TVN [Member]
Restructuring Cost and Reserve [Line Items]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Curtailments								$ 2,000
Business Combination, Acquisition and Integration Related Expenses					6,500		6,500	16,900
Business Combination, Integration Related Costs			467		$ 2,518	$ 2,617	$ 3,178
Number of employees applied for VDP | Employees				83
Voluntary Departure Plan Anticipated Cost								$ 15,300
Voluntary Departure Plan Benefit Obligation Term								4 years
Number of employees required to work beyond minimum statutory notice period under VDP | Employees				11
Accrued Voluntary Departure Plan, Current				$ 14,800				$ 14,800
TVN [Member] | Employee Severance And Benefit Arrangements [Member] | Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Number of positions eliminated						21		83
TVN [Member] | Employee Severance [Member] | Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Postemployment Benefits, Period Expense			700			$ 1,800
Charges for 2016 Harmonic Restructuring Plan			400			1,000
TVN [Member] | TVN Voluntary Departure Plan [Member]
Restructuring Cost and Reserve [Line Items]
Charges for 2016 Harmonic Restructuring Plan						1,800		$ 13,100
Defined Benefit Plan, Benefits Paid						4,900		$ 3,500	$ 8,400
Postemployment Benefits Liability			$ 7,200			$ 7,200			$ 7,200
San Jose CA Excess Facility [Member] | Facility Closing [Member] | Harmonic 2016 Restructuring Plan [Member]
Restructuring Cost and Reserve [Line Items]
Charges for 2016 Harmonic Restructuring Plan		$ 1,400
Fair Value of Excess Facility Restructuring										$ 2,500
Deferred Rent Credit										$ 1,100
Adjustments to restructuring provisions				$ 600

[1] The Company anticipates that the remaining severance and benefits accrual at June 30, 2017 will be fully paid in 2017.

[2] See discussion of the TVN VDP above for future estimated payments through 2020.