Legal Proceedings	12 Months Ended
Dec. 31, 2014
Loss Contingency [Abstract]
Legal Proceedings	LEGAL PROCEEDINGS From time to time, the Company is involved in lawsuits as well as subject to various legal proceedings, claims, threats of litigation, and investigations in the ordinary course of business, including claims of alleged infringement of third-party patents and other intellectual property rights, commercial, employment, and other matters. The Company assesses potential liabilities in connection with each lawsuit and threatened lawsuits and accrues an estimated loss for these loss contingencies if both of the following conditions are met: information available prior to issuance of the financial statements indicates that it is probable that a liability has been incurred at the date of the financial statements and the amount of loss can be reasonably estimated. While certain matters to which the Company is a party specify the damages claimed, such claims may not represent reasonably probable losses. Given the inherent uncertainties of litigation, the ultimate outcome of these matters cannot be predicted at this time, nor can the amount of possible loss or range of loss, if any, be reasonably estimated. In October 2011, Avid Technology, Inc. (“Avid”) filed a complaint in the United States District Court for the District of Delaware alleging that Harmonic’s Media Grid product infringes two patents held by Avid. A jury trial on this complaint commenced on January 23, 2014 and, on February 4, 2014, the jury returned a unanimous verdict in favor of Harmonic, rejecting Avid's infringement allegations in their entirety. On May 23, 2014, Avid filed a post-trial motion asking the court to set aside the jury’s verdict, and the judge issued an order on December 17, 2014, denying the motion. On January 5, 2015, Avid filed an appeal with respect to the jury’s verdict with the Federal Circuit, which was docketed on January 9, 2015, as Case No. 2015-1246. In June 2012, Avid served a subsequent complaint in the United States District Court for the District of Delaware alleging that Harmonic’s Spectrum product infringes one patent held by Avid. The complaint seeks injunctive relief and unspecified damages. On September 25, 2013, the U.S. Patent Trial and Appeal Board ("PTAB") authorized an inter partes review to be instituted as to claims 1-16 of the patent asserted in this second complaint. A hearing before the PTAB was conducted on May 20, 2014. On July 10, 2014, the PTAB issued a decision finding claims 1 - 10 invalid and claims 11 - 16 not invalid. Harmonic filed an appeal with respect to the PTAB’s decision on claims 11 - 16 on September 11, 2014. The appeal was docketed with the Federal Circuit on October 22, 2014, as Case No. 2015-1072, and Harmonic filed its opening brief with respect to this appeal on January 29, 2015. An unfavorable outcome on any litigation matters could require that Harmonic pay substantial damages, or, in connection with any intellectual property infringement claims, could require that the Company pay ongoing royalty payments or could prevent the Company from selling certain of its products. As a result, a settlement of, or an unfavorable outcome on, any of the matters referenced above or other litigation matters could have a material adverse effect on Harmonic’s business, operating results, financial position and cash flows.

LEGAL PROCEEDINGS

From time to time, the Company is involved in lawsuits as well as subject to various legal proceedings, claims, threats of litigation, and investigations in the ordinary course of business, including claims of alleged infringement of third-party patents and other intellectual property rights, commercial, employment, and other matters. The Company assesses potential liabilities in connection with each lawsuit and threatened lawsuits and accrues an estimated loss for these loss contingencies if both of the following conditions are met: information available prior to issuance of the financial statements indicates that it is probable that a liability has been incurred at the date of the financial statements and the amount of loss can be reasonably estimated. While certain matters to which the Company is a party specify the damages claimed, such claims may not represent reasonably probable losses. Given the inherent uncertainties of litigation, the ultimate outcome of these matters cannot be predicted at this time, nor can the amount of possible loss or range of loss, if any, be reasonably estimated.

In October 2011, Avid Technology, Inc. (“Avid”) filed a complaint in the United States District Court for the District of Delaware alleging that Harmonic’s Media Grid product infringes two patents held by Avid. A jury trial on this complaint commenced on January 23, 2014 and, on February 4, 2014, the jury returned a unanimous verdict in favor of Harmonic, rejecting Avid's infringement allegations in their entirety. On May 23, 2014, Avid filed a post-trial motion asking the court to set aside the jury’s verdict, and the judge issued an order on December 17, 2014, denying the motion. On January 5, 2015, Avid filed an appeal with respect to the jury’s verdict with the Federal Circuit, which was docketed on January 9, 2015, as Case No. 2015-1246.

In June 2012, Avid served a subsequent complaint in the United States District Court for the District of Delaware alleging that Harmonic’s Spectrum product infringes one patent held by Avid. The complaint seeks injunctive relief and unspecified damages. On September 25, 2013, the U.S. Patent Trial and Appeal Board ("PTAB") authorized an inter partes review to be instituted as to claims 1-16 of the patent asserted in this second complaint. A hearing before the PTAB was conducted on May 20, 2014. On July 10, 2014, the PTAB issued a decision finding claims 1 - 10 invalid and claims 11 - 16 not invalid. Harmonic filed an appeal with respect to the PTAB’s decision on claims 11 - 16 on September 11, 2014. The appeal was docketed with the Federal Circuit on October 22, 2014, as Case No. 2015-1072, and Harmonic filed its opening brief with respect to this appeal on January 29, 2015.

An unfavorable outcome on any litigation matters could require that Harmonic pay substantial damages, or, in connection with any intellectual property infringement claims, could require that the Company pay ongoing royalty payments or could prevent the Company from selling certain of its products. As a result, a settlement of, or an unfavorable outcome on, any of the matters referenced above or other litigation matters could have a material adverse effect on Harmonic’s business, operating results, financial position and cash flows.