Interim Financial Statements	3 Months Ended
Interim Financial Statements	Apr. 30, 2011
Interim Financial Statements [Abstract]
INTERIM FINANCIAL STATEMENTS	(1) INTERIM FINANCIAL STATEMENTS The interim financial statements included herein for Ciena Corporation (“Ciena”) have been prepared by Ciena, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission. In the opinion of management, financial statements included in this report reflect all normal recurring adjustments that Ciena considers necessary for the fair statement of the results of operations for the interim periods covered and of the financial position of Ciena at the date of the interim balance sheets. Certain information and footnote disclosures normally included in the annual financial statements prepared in accordance with generally accepted accounting principles have been condensed or omitted pursuant to such rules and regulations. The October 31, 2010 Condensed Consolidated Balance Sheet was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America. However, Ciena believes that the disclosures are adequate to understand the information presented. The operating results for interim periods are not necessarily indicative of the operating results for the entire year. These financial statements should be read in conjunction with Ciena’s audited consolidated financial statements and notes thereto included in Ciena’s annual report on Form 10-K for the fiscal year ended October 31, 2010. On March 19, 2010, Ciena completed its acquisition of substantially all of the optical networking and Carrier Ethernet assets of Nortel’s Metro Ethernet Networks (“MEN Business”). Ciena’s results of operations for the second quarter and six-month period ended April 30, 2010 reflect the operations of the MEN Business beginning on the March 19, 2010 acquisition date. See Note 3 below. Ciena has a 52 or 53 week fiscal year, which ends on the Saturday nearest to the last day of October of each year. For purposes of financial statement presentation, each fiscal year is described as having ended on October 31, and each fiscal quarter is described as having ended on January 31, April 30 and July 31 of each fiscal year.

Description containing the entire organization, consolidation and basis of presentation of financial statements disclosure. May be provided in more than one note to the financial statements, as long as users are provided with an understanding of (1) the significant judgments and assumptions made by an enterprise in determining whether it must consolidate a VIE and/or disclose information about its involvement with a VIE, (2) the nature of restrictions on a consolidated VIE's assets reported by an enterprise in its statement of financial position, including the carrying amounts of such assets, (3) the nature of, and changes in, the risks associated with an enterprise's involvement with the VIE, and (4) how an enterprise's involvement with the VIE affects the enterprise's financial position, financial performance, and cash flows. Describes procedure if disclosures are provided in more than one note to the financial statements.

+ References+ Details