Employee Benefit Plans - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for grant	10,155,000	7,835,000
Intrinsic value of options exercised	$ 800,000	$ 5,200,000	$ 1,000,000
Discretionary contributions of plan	25.00%
Percentage of contribution by eligible participants	4.00%
Maximum contribution per participant	1,000
Defined contribution plan description	This plan allows participants to contribute up to the applicable Internal Revenue Code limitations under the plan. Harmonic can make discretionary contributions to the plan of 25% of the first 4% contributed by eligible participants, up to a maximum contribution per participant of $1,000 per year. Employer contributions were suspended from 2009 through 2012, but have been renewed, on the same basis, for 2013.
Assumed Unvested Stock Option [Member] | Omneon [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of assumed options to be issued under the assumed acquisition stock plans	1,522,000
Assumed unvested restricted stock units [Member] | Omneon [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of assumed options to be issued under the assumed acquisition stock plans	1,455,000
2002 Director Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price at which non-statutory stock options may be granted	Not less than 100% of the fair value
Common stock reserved for issuance	872,513
Shares available for grant	350,912
Share based compensation arrangement vesting period	Both options and RSUs vest over a period of time as determined by the Board of Directors, generally three years for the initial grant and one year for subsequent grants to a non-employee director, and expire seven years from date of grant
Exercise price of RSUs	$ 0
Reduced the number of shares reserved for every unit granted	1.5
Increased number of shares reserved for every unit forfeited	1.5
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance	1,230,891
Percentage of fair market value of Common Stock to purchase shares	85.00%
Range of payroll deduction	1% to 10%
Common stock issued under the 2002 ESPP	1,598,895	945,287	864,800
Stock contributions value under 2002 ESPP	$ 6,400,000	$ 5,200,000	$ 4,200,000
Total number of shares issued under plan	8,269,109
Other Stock Option Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for issuance	306,882
1995 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Price at which incentive stock options may be granted	Not less than 100% of the fair value
Price at which non-statutory stock options may be granted	Not less than 85% of the fair value
Maximum term of stock options granted	7 years
Decrease in plan reserve for every unit	1.5 shares for every unit or share granted
Increase in plan reserve for every unit	1.5 shares for every unit or share forfeited
Common stock reserved for issuance	21,108,836
Shares available for grant	9,804,018
Share based compensation arrangement vesting period	Vest over four years and expire seven years from date of grant. Options granted prior to February 2006 expire in ten years.
1995 Stock Plan [Member] | Options and Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term of stock options granted	10 years
1995 Stock Plan [Member] | Options and Restricted Stock Units [Member] | Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock vesting period	3 years
1995 Stock Plan [Member] | Options and Restricted Stock Units [Member] | Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock vesting period	4 years
Assumed Omneon Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock vesting period	4 years
Maximum term of stock options granted	10 years
Common stock reserved for issuance	702,512
Assumed Omneon Stock Options [Member] | Assumed Unvested Stock Option [Member] | Omneon [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of assumed options to be issued under the assumed acquisition stock plans	1,522,000
Assumed Omneon Stock Options [Member] | Assumed unvested restricted stock units [Member] | Omneon [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of assumed options to be issued under the assumed acquisition stock plans	1,455,000
Assumed Omneon Stock Options [Member] | Options and Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock vesting period	4 years
Maximum term of stock options granted	10 years