Commitments and Contingencies	9 Months Ended
Jul. 31, 2013
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Ontario Grant Ciena was awarded a conditional grant from the Province of Ontario in June 2011. Under this strategic jobs investment fund grant, Ciena can receive up to an aggregate of C$25.0 million in funding for eligible costs relating to certain next-generation, coherent optical transport development initiatives over the period from November 1, 2010 to October 31, 2015. Ciena anticipates receiving disbursements, approximating C$5.0 million per fiscal year, over the period above. Amounts received under the grant are subject to recoupment in the event that Ciena fails to achieve certain minimum investment, employment and project milestones. As of July 31, 2013, Ciena has recorded a C$15.0 million benefit to date as a reduction in research and development expenses, of which C$4.1 million was recorded in the first nine months of fiscal 2013. As of July 31, 2013, amounts receivable from this grant were C$1.2 million. Foreign Tax Contingencies Ciena has previously received assessment notices from Mexican tax authorities asserting deficiencies in payments between 2001 and 2005, related primarily to income taxes and import taxes and duties. Ciena previously submitted judicial petitions appealing these assessments. As of October 31, 2012 and April 30, 2013, Ciena had accrued liabilities of $1.7 million and $2.0 million, respectively, related to these foreign tax contingencies. During the third quarter of fiscal 2013, Ciena received a favorable resolution of these matters with the tax court issuing a final and non-appealable declaration determining such tax assessments to be null and void. As a result, Ciena reversed the accrued liability related to this foreign tax contingency. In addition to the matters described above, Ciena is subject to various tax liabilities arising in the ordinary course of business. Ciena does not expect that the ultimate settlement of these liabilities will have a material effect on its results of operations, financial position or cash flows. Litigation On July 26, 2013, Ciena and Cheetah Omni LLC entered into a settlement agreement relating to patent litigation pending in the United States District Court for the Eastern District of Texas. The proceeding arose on July 29, 2011, when Cheetah Omni filed a complaint against Ciena and several other defendants alleging that certain of the parties' products infringe upon multiple U.S. patents relating to reconfigurable optical add-drop multiplexer (ROADM) technologies. The complaint sought injunctive relief and damages. Under the terms of the settlement, Ciena agreed to make a one-time payment of $1.5 million to Cheetah Omni in exchange for a fully paid-up license to all of the patents-in-suit, a release from all claims for damages and other relief relating to such patents, and a covenant not to sue Ciena at any time on any non-medical patents owned by or assigned to Cheetah Omni on the effective date of the settlement agreement and through July 26, 2017. On August 9, 2013, the district court granted the parties' joint stipulation of dismissal with prejudice. On May 29, 2008, Graywire, LLC filed a complaint in the United States District Court for the Northern District of Georgia against Ciena and four other defendants, alleging, among other things, that certain of the parties' products infringe U.S. Patent 6,542,673 (the “'673 Patent”), relating to an identifier system and components for optical assemblies. The complaint seeks injunctive relief and damages. In July 2009, upon request of Ciena and certain other defendants, the U.S. Patent and Trademark Office (“PTO”) granted the defendants' inter partes application for reexamination with respect to certain claims of the '673 Patent, and the district court granted the defendants' motion to stay the case pending reexamination of all of the patents-in-suit. In December 2010, the PTO confirmed the validity of some claims and rejected the validity of other claims of the '673 Patent, to which Ciena and other defendants filed an appeal. On March 16, 2012, the PTO on appeal rejected multiple claims of the '673 Patent, including the two claims on which Ciena is alleged to infringe. Subsequently, the plaintiff requested a reopening of the prosecution of the '673 Patent, which request was denied by the PTO on April 29, 2013. Thereafter, on May 28, 2013, the plaintiff filed an amendment with the PTO in which it canceled the claims of the '673 Patent on which Ciena is alleged to infringe. The case currently remains stayed, and there can be no assurance as to whether or when the stay will be lifted. In addition to the matters described above, Ciena is subject to various legal proceedings and claims arising in the ordinary course of business, including claims against third parties that may involve contractual indemnification obligations on the part of Ciena. Ciena does not expect that the ultimate costs to resolve these matters will have a material effect on its results of operations, financial position or cash flows.

COMMITMENTS AND CONTINGENCIES

Ontario Grant

Ciena was awarded a conditional grant from the Province of Ontario in June 2011. Under this strategic jobs investment fund grant, Ciena can receive up to an aggregate of C$25.0 million in funding for eligible costs relating to certain next-generation, coherent optical transport development initiatives over the period from November 1, 2010 to October 31, 2015. Ciena anticipates receiving disbursements, approximating C$5.0 million per fiscal year, over the period above. Amounts received under the grant are subject to recoupment in the event that Ciena fails to achieve certain minimum investment, employment and project milestones. As of July 31, 2013, Ciena has recorded a C$15.0 million benefit to date as a reduction in research and development expenses, of which C$4.1 million was recorded in the first nine months of fiscal 2013. As of July 31, 2013, amounts receivable from this grant were C$1.2 million.

Foreign Tax Contingencies

Ciena has previously received assessment notices from Mexican tax authorities asserting deficiencies in payments between 2001 and 2005, related primarily to income taxes and import taxes and duties. Ciena previously submitted judicial petitions appealing these assessments. As of October 31, 2012 and April 30, 2013, Ciena had accrued liabilities of $1.7 million and $2.0 million, respectively, related to these foreign tax contingencies. During the third quarter of fiscal 2013, Ciena received a favorable resolution of these matters with the tax court issuing a final and non-appealable declaration determining such tax assessments to be null and void. As a result, Ciena reversed the accrued liability related to this foreign tax contingency.

In addition to the matters described above, Ciena is subject to various tax liabilities arising in the ordinary course of business. Ciena does not expect that the ultimate settlement of these liabilities will have a material effect on its results of operations, financial position or cash flows.

Litigation

On July 26, 2013, Ciena and Cheetah Omni LLC entered into a settlement agreement relating to patent litigation pending in the United States District Court for the Eastern District of Texas. The proceeding arose on July 29, 2011, when Cheetah Omni filed a complaint against Ciena and several other defendants alleging that certain of the parties' products infringe upon multiple U.S. patents relating to reconfigurable optical add-drop multiplexer (ROADM) technologies. The complaint sought injunctive relief and damages. Under the terms of the settlement, Ciena agreed to make a one-time payment of $1.5 million to Cheetah Omni in exchange for a fully paid-up license to all of the patents-in-suit, a release from all claims for damages and other relief relating to such patents, and a covenant not to sue Ciena at any time on any non-medical patents owned by or assigned to Cheetah Omni on the effective date of the settlement agreement and through July 26, 2017. On August 9, 2013, the district court granted the parties' joint stipulation of dismissal with prejudice.

On May 29, 2008, Graywire, LLC filed a complaint in the United States District Court for the Northern District of Georgia against Ciena and four other defendants, alleging, among other things, that certain of the parties' products infringe U.S. Patent 6,542,673 (the “'673 Patent”), relating to an identifier system and components for optical assemblies. The complaint seeks injunctive relief and damages. In July 2009, upon request of Ciena and certain other defendants, the U.S. Patent and Trademark Office (“PTO”) granted the defendants' inter partes application for reexamination with respect to certain claims of the '673 Patent, and the district court granted the defendants' motion to stay the case pending reexamination of all of the patents-in-suit. In December 2010, the PTO confirmed the validity of some claims and rejected the validity of other claims of the '673 Patent, to which Ciena and other defendants filed an appeal. On March 16, 2012, the PTO on appeal rejected multiple claims of the '673 Patent, including the two claims on which Ciena is alleged to infringe. Subsequently, the plaintiff requested a reopening of the prosecution of the '673 Patent, which request was denied by the PTO on April 29, 2013. Thereafter, on May 28, 2013, the plaintiff filed an amendment with the PTO in which it canceled the claims of the '673 Patent on which Ciena is alleged to infringe. The case currently remains stayed, and there can be no assurance as to whether or when the stay will be lifted.

In addition to the matters described above, Ciena is subject to various legal proceedings and claims arising in the ordinary course of business, including claims against third parties that may involve contractual indemnification obligations on the part of Ciena. Ciena does not expect that the ultimate costs to resolve these matters will have a material effect on its results of operations, financial position or cash flows.