Litigation	12 Months Ended
May 03, 2015
Commitments and Contingencies Disclosure [Abstract]
Litigation	Litigation The Company accrues a liability for legal contingencies when it believes that it is both probable that a liability has been incurred and that it can reasonably estimate the amount of the loss. The Company reviews these accruals and adjusts them to reflect ongoing negotiations, settlements, rulings, advice of legal counsel and other relevant information. To the extent new information is obtained and the Company's views on the probable outcomes of claims, suits, assessments, investigations or legal proceedings change, changes in the Company's accrued liabilities would be recorded in the period in which such determination is made. For the matters referenced below, the amount of liability is not probable or the amount cannot be reasonably estimated and, therefore, accruals have not been made. In addition, in accordance with the relevant authoritative guidance, for matters which the likelihood of material loss is at least reasonably possible, the Company provides disclosure of the possible loss or range of loss; however, if a reasonable estimate cannot be made, the Company will provide disclosure to that effect. Due to the nature of the Company's business, it is subject to claims alleging infringement by various Company products and services. The Company believes that it has meritorious defenses to the allegations made in its pending cases and intends to vigorously defend these lawsuits; however, it is unable currently to determine the ultimate outcome of these or similar matters. In addition, the Company is a defendant in various litigation matters generally arising out of the normal course of business. Although it is difficult to predict the ultimate outcomes of these cases, the Company believes that it is not reasonably possible that the ultimate outcomes will materially and adversely affect its business, financial position, results of operations or cash flows. Class Action and Shareholder Derivative Litigation Several securities class action lawsuits related to the Company's March 8, 2011 earnings announcement alleging claims under Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 have been filed in the United States District Court for the Northern District of California on behalf of a purported class of persons who purchased stock between December 1 or 2, 2010 through March 8, 2011. The named defendants are the Company and its Chairman of the Board, Chief Executive Officer and Chief Financial Officer. To date, no specific amount of damages have been alleged. The cases were consolidated, lead plaintiffs were appointed and a consolidated complaint was filed. The Company filed a motion to dismiss the case. On January 16, 2013, the District Court granted the Company's motion to dismiss and granted the lead plaintiffs leave to amend the consolidated complaint. An amended consolidated complaint was filed on February 6, 2013. Thereafter, the Company filed a renewed motion to dismiss the case. On September 30, 2013, the District Court granted the Company's motion and dismissed the case with prejudice. On October 25, 2013, the lead plaintiffs filed a notice of appeal of the District Court's dismissal ruling, and the appeal is pending. In addition, two purported shareholder derivative lawsuits related to the Company's March 8, 2011 earnings announcement have been filed in the California Superior Court for the County of Santa Clara, and a third derivative lawsuit has been filed in the United States District Court for the Northern District of California. The complaints assert claims for alleged breach of fiduciary duty, unjust enrichment, and waste on behalf of the Company. Named as defendants are the members of the Company's board of directors, including the Company's Chairman of the Board and Chief Executive Officer, and its Chief Financial Officer. No specific amount of damages has been alleged and, by the derivative nature of the lawsuits, no damages will be alleged, against the Company. The state court cases have been consolidated and a lead plaintiff has been appointed to file a consolidated complaint. The derivative cases were stayed pending a ruling in the federal class action case. Following the September 30 ruling dismissing the class action case, the derivative cases remain stayed, subject to the right of the parties to reinstate them. Thomas Swan Litigation On February 26, 2013, Thomas Swan & Co. Ltd. filed a complaint for patent infringement in the United States District Court for the Eastern District of Texas against the Company. The complaint alleges that Finisar's WSS products, ROADM line cards containing a Finisar WSS, and Waveshaper products infringe four related Thomas Swan patents. The Company's customer, Fujitsu Network Communications, was added as a co-defendant in this lawsuit. The Company has performed a review of the asserted patents and believes that the patent claims are not infringed and/or are invalid. In October 2014, the parties reached a confidential agreement to settle this lawsuit. The Company evaluated the transaction as a multiple-element arrangement and allocated the one-time payment of $11.0 million that the Company is obligated to make to the plaintiff in connection with the settlement to each identifiable element using its estimates of relative fair values of these elements. The Company determined that the primary benefits of the arrangement are avoided litigation cost and elimination of use of the Company's management and personnel resources, with no material value attributable to future use or benefit. Accordingly, the Company recorded an $11.0 million settlement charge as general and administrative expenses in the consolidated statements of operations for the quarter ended October 26, 2014. Mears Technologies Litigation On May 6, 2013, Mears Technologies, Inc. filed a complaint for patent infringement in the United States District Court for the Eastern District of Texas against the Company. The complaint alleges that Finisar's WSS products, ROADM line cards containing a Finisar WSS, and Waveshaper products infringe U.S. Patent No. 6,141,361. The Company has performed a review of the asserted patent and believes that the patent claims are not infringed and/or are invalid. On June 17, 2014, the district court issued a claim construction order favorable to the Company. On October 6, 2014, the court denied a motion of the plaintiff to amend its infringement contentions in light of the court’s claim construction ruling. As a result, the plaintiff has conceded that it is unable to pursue its infringement claims against the Company. On December 30, 2014, the court granted the Company’s motion for summary judgment of non-infringement. The plaintiff has indicated that it intends to appeal the court’s claim construction ruling and the court’s denial of the plaintiff’s motion to amend its infringement contentions in light of the court’s claim construction ruling. The Company intends to oppose any such appeal vigorously. However, if the plaintiff’s appeal is wholly or partially successful, the case would be revived in the United States District Court for the Eastern District of Texas. If the appeal succeeds and the case resumes, the Company may be liable for substantial damages. Even if the defense of any resumed case is successful, the Company may incur substantial legal fees and other costs in defending the lawsuit. Further, the lawsuit could divert the efforts and attention of the Company's management and technical personnel, which could harm its business. Other In the ordinary course of business, the Company is a party to litigation, claims and assessments in addition to those described above. Based on information currently available, management does not believe the impact of these other matters will have a material adverse effect on its business, financial condition, results of operations or cash flows of the Company.

Litigation

The Company accrues a liability for legal contingencies when it believes that it is both probable that a liability has been incurred and that it can reasonably estimate the amount of the loss. The Company reviews these accruals and adjusts them to reflect ongoing negotiations, settlements, rulings, advice of legal counsel and other relevant information. To the extent new information is obtained and the Company's views on the probable outcomes of claims, suits, assessments, investigations or legal proceedings change, changes in the Company's accrued liabilities would be recorded in the period in which such determination is made. For the matters referenced below, the amount of liability is not probable or the amount cannot be reasonably estimated and, therefore, accruals have not been made. In addition, in accordance with the relevant authoritative guidance, for matters which the likelihood of material loss is at least reasonably possible, the Company provides disclosure of the possible loss or range of loss; however, if a reasonable estimate cannot be made, the Company will provide disclosure to that effect.

Due to the nature of the Company's business, it is subject to claims alleging infringement by various Company products and services. The Company believes that it has meritorious defenses to the allegations made in its pending cases and intends to vigorously defend these lawsuits; however, it is unable currently to determine the ultimate outcome of these or similar matters. In addition, the Company is a defendant in various litigation matters generally arising out of the normal course of business. Although it is difficult to predict the ultimate outcomes of these cases, the Company believes that it is not reasonably possible that the ultimate outcomes will materially and adversely affect its business, financial position, results of operations or cash flows.

Class Action and Shareholder Derivative Litigation

Several securities class action lawsuits related to the Company's March 8, 2011 earnings announcement alleging claims under Sections 10(b) and 20(a) of the Securities Exchange Act of 1934 have been filed in the United States District Court for the Northern District of California on behalf of a purported class of persons who purchased stock between December 1 or 2, 2010 through March 8, 2011. The named defendants are the Company and its Chairman of the Board, Chief Executive Officer and Chief Financial Officer. To date, no specific amount of damages have been alleged. The cases were consolidated, lead plaintiffs were appointed and a consolidated complaint was filed. The Company filed a motion to dismiss the case. On January 16, 2013, the District Court granted the Company's motion to dismiss and granted the lead plaintiffs leave to amend the consolidated complaint. An amended consolidated complaint was filed on February 6, 2013. Thereafter, the Company filed a renewed motion to dismiss the case. On September 30, 2013, the District Court granted the Company's motion and dismissed the case with prejudice. On October 25, 2013, the lead plaintiffs filed a notice of appeal of the District Court's dismissal ruling, and the appeal is pending.

In addition, two purported shareholder derivative lawsuits related to the Company's March 8, 2011 earnings announcement have been filed in the California Superior Court for the County of Santa Clara, and a third derivative lawsuit has been filed in the United States District Court for the Northern District of California. The complaints assert claims for alleged breach of fiduciary duty, unjust enrichment, and waste on behalf of the Company. Named as defendants are the members of the Company's board of directors, including the Company's Chairman of the Board and Chief Executive Officer, and its Chief Financial Officer. No specific amount of damages has been alleged and, by the derivative nature of the lawsuits, no damages will be alleged, against the Company. The state court cases have been consolidated and a lead plaintiff has been appointed to file a consolidated complaint. The derivative cases were stayed pending a ruling in the federal class action case. Following the September 30 ruling dismissing the class action case, the derivative cases remain stayed, subject to the right of the parties to reinstate them.

Thomas Swan Litigation

On February 26, 2013, Thomas Swan & Co. Ltd. filed a complaint for patent infringement in the United States District Court for the Eastern District of Texas against the Company. The complaint alleges that Finisar's WSS products, ROADM line cards containing a Finisar WSS, and Waveshaper products infringe four related Thomas Swan patents. The Company's customer, Fujitsu Network Communications, was added as a co-defendant in this lawsuit. The Company has performed a review of the asserted patents and believes that the patent claims are not infringed and/or are invalid. In October 2014, the parties reached a confidential agreement to settle this lawsuit. The Company evaluated the transaction as a multiple-element arrangement and allocated the one-time payment of $11.0 million that the Company is obligated to make to the plaintiff in connection with the settlement to each identifiable element using its estimates of relative fair values of these elements. The Company determined that the primary benefits of the arrangement are avoided litigation cost and elimination of use of the Company's management and personnel resources, with no material value attributable to future use or benefit. Accordingly, the Company recorded an $11.0 million settlement charge as general and administrative expenses in the consolidated statements of operations for the quarter ended October 26, 2014.

Mears Technologies Litigation

On May 6, 2013, Mears Technologies, Inc. filed a complaint for patent infringement in the United States District Court for the Eastern District of Texas against the Company. The complaint alleges that Finisar's WSS products, ROADM line cards containing a Finisar WSS, and Waveshaper products infringe U.S. Patent No. 6,141,361. The Company has performed a review of the asserted patent and believes that the patent claims are not infringed and/or are invalid. On June 17, 2014, the district court issued a claim construction order favorable to the Company. On October 6, 2014, the court denied a motion of the plaintiff to amend its infringement contentions in light of the court’s claim construction ruling. As a result, the plaintiff has conceded that it is unable to pursue its infringement claims against the Company. On December 30, 2014, the court granted the Company’s motion for summary judgment of non-infringement. The plaintiff has indicated that it intends to appeal the court’s claim construction ruling and the court’s denial of the plaintiff’s motion to amend its infringement contentions in light of the court’s claim construction ruling. The Company intends to oppose any such appeal vigorously. However, if the plaintiff’s appeal is wholly or partially successful, the case would be revived in the United States District Court for the Eastern District of Texas. If the appeal succeeds and the case resumes, the Company may be liable for substantial damages. Even if the defense of any resumed case is successful, the Company may incur substantial legal fees and other costs in defending the lawsuit. Further, the lawsuit could divert the efforts and attention of the Company's management and technical personnel, which could harm its business.

Other

In the ordinary course of business, the Company is a party to litigation, claims and assessments in addition to those described above. Based on information currently available, management does not believe the impact of these other matters will have a material adverse effect on its business, financial condition, results of operations or cash flows of the Company.