Omneon Acquisition - Additional Information (Detail) (USD $)	3 Months Ended								12 Months Ended			3 Months Ended	12 Months Ended			12 Months Ended				12 Months Ended
	Dec. 31, 2012	Sep. 28, 2012	Jun. 29, 2012	Mar. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 30, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2010 Omneon [Member]	Dec. 31, 2012 Omneon [Member]	Sep. 15, 2010 Omneon [Member]	Sep. 15, 2010 Omneon [Member] Equity Issued in Business Combination [Member]	Dec. 31, 2012 Omneon [Member] Assumed Unvested Stock Option [Member]	Dec. 31, 2012 Omneon [Member] Assumed unvested restricted stock units [Member]	Sep. 15, 2010 Omneon [Member] Common Stock [Member]	Sep. 15, 2010 Omneon [Member] Assumed Vested Award [Member]	Dec. 31, 2012 Omneon [Member] Existing technology [Member]	Dec. 31, 2012 Omneon [Member] Customer Contracts [Member]	Dec. 31, 2012 Omneon [Member] Patents and core technology [Member]	Dec. 31, 2012 Omneon [Member] In-process technology [Member]	Dec. 31, 2012 Omneon [Member] Maintenance agreements [Member]	Dec. 31, 2012 Omneon [Member] Trade names/trademarks [Member]	Dec. 31, 2012 Omneon [Member] Order backlog [Member]
Business Acquisition [Line Items]
Equity interest acquired														100.00%
Reason for business combination									Omneon was engaged in the development and support of a range of video servers, active storage systems and related software applications that media companies use to simultaneously ingest, process, store, manage and deliver digital media in a wide range of formats. The acquisition of Omneon was intended to strengthen Harmonic's competitive position in the digital media market and to broaden the Company's relationships with customers who produce and distribute digital video content, such as broadcasters, content networks and other major owners of content. The acquisition was also intended to broaden Harmonic's technology and product lines with digital storage and playout solutions which complement Harmonic's existing video processing products. In addition, the acquisition provided an assembled workforce and the implicit value of future cost savings as a result of combining entities, and was expected to provide Harmonic with future, but then unidentified, new products and technologies.
Goodwill	$ 212,518,000				$ 212,417,000				$ 212,518,000	$ 212,417,000	$ 211,878,000		$ 147,750,000	$ 147,800,000
Cash net of purchase price													40,485,000	40,500,000
Total purchase consideration net of cash received														251,300,000
Purchase price paid as net of cash														153,300,000
Number of common stocks paid as purchase price															14,200,000
Fair value of equity awards included in purchase consideration													2,100,000					95,900,000	2,100,000
Transaction expenses												5,900,000
Cash deposited to secure post-closing indemnification obligations of holders														21,000,000
Number of common stock deposited to secure post-closing indemnification obligations of holders									1,926,920		1,926,920
Reimbursement amount received from escrow				800,000
Reimbursement amount received from escrow in cash				500,000
Reimbursement amount received from escrow in common stock, shares				40,372
Reimbursement amount received from escrow common stock, amount				300,000
Number of shares to be purchased under equity awards																1,522,000	1,455,000
Fair value of stock options and restricted stock units issued to employees													17,300,000
Compensation expense to be recorded for stock options and restricted stock	25,100,000								25,100,000				15,200,000
Weighted average service period									2 years 4 months 24 days				2 years 6 months
Estimated useful life of intangible assets																				4 years	6 years	4 years	4 years	6 years	4 years	3 months 15 days
Goodwill recognized in business combination, description									Goodwill. Goodwill is calculated as the excess of the purchase price over the fair value of the underlying net tangible and identifiable intangible assets acquired. Goodwill represents the highly skilled and valuable assembled workforce, the ability to generate new products and services as a combined company and expected synergistic benefits of the transaction. In accordance with applicable accounting standards, goodwill is not amortized, but instead will be tested for impairment at least annually or more frequently if certain indicators are present. The goodwill resulting from this acquisition is not deductible for federal tax purposes.
Net revenue, total									530,464,000	549,332,000	423,344,000	36,500,000
Operating profit	$ 2,694,000	$ (949,000)	$ (2,395,000)	$ (8,657,000)	$ 6,627,000	$ 3,840,000	$ 1,393,000	$ (87,000)	$ (9,307,000)	$ 11,773,000	$ 5,142,000	$ 1,100,000