Restructuring and Excess Facilities - Activities in Restructuring Accrual (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Dec. 31, 2010	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Restructuring Cost and Reserve [Line Items]
Provisions		$ 1,421	$ 0	$ 0
Omneon Restructuring [Member] | Excess Facilities [Member]
Restructuring Cost and Reserve [Line Items]
Beginning Balance		869	2,593	2,862
Provisions	3,000	28	94	517
Cash payments, net of sublease income		(897)	(1,818)	(786)
Ending Balance	2,862	0	869	2,593
HFC Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges in discontinued operations		527
Adjustments to restructuring provisions		73
Cash payments		(587)
Ending Balance		13
HFC Restructuring [Member] | Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges in discontinued operations		403
Adjustments to restructuring provisions		102
Cash payments		(492)
Ending Balance		13
HFC Restructuring [Member] | Contract Termination [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges in discontinued operations		124
Adjustments to restructuring provisions		(29)
Cash payments		(95)
Ending Balance		0
Harmonic 2013 Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Provisions		2,200
Restructuring charges in continued operations		2,168
Adjustments to restructuring provisions		77
Cash payments		(1,513)
Non-cash write-offs		(553)
Ending Balance		179
Harmonic 2013 Restructuring [Member] | Severance [Member]
Restructuring Cost and Reserve [Line Items]
Provisions		1,700
Restructuring charges in continued operations		1,663
Adjustments to restructuring provisions		29
Cash payments		(1,513)
Non-cash write-offs		0
Ending Balance		179
Harmonic 2013 Restructuring [Member] | Impairment of Leasehold Improvements [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges in continued operations		101
Adjustments to restructuring provisions		48
Cash payments		0
Non-cash write-offs		(149)
Ending Balance		0
Harmonic 2013 Restructuring [Member] | Obsolete Inventories [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring charges in continued operations		404
Adjustments to restructuring provisions		0
Cash payments		0
Non-cash write-offs		(404)
Ending Balance		$ 0