Goodwill and Long-Lived Asset Assessment	12 Months Ended
Oct. 31, 2011
Goodwill and Long-Lived Asset Assessment Disclosure [Abstract]
GOODWILL AND LONG-LIVED ASSET ASSESSMENT	GOODWILL AND LONG-LIVED ASSET IMPAIRMENTS Goodwill As of October 31, 2010 and 2011, Ciena did not have any goodwill on its Consolidated Balance Sheets. Prior to the acquisition of the MEN Business, Ciena assessed its goodwill based upon a single reporting unit and tested its single reporting unit’s goodwill for impairment annually on the last business day of fiscal September each year. Testing is required between annual tests if events occur or circumstances change that would, more likely than not, reduce the fair value of the reporting unit below its carrying value. Based on a combination of factors, including macroeconomic conditions and a sustained decline in Ciena’s common stock price and market capitalization below net book value, Ciena conducted an interim impairment assessment of goodwill during the second quarter of fiscal 2009. Ciena performed the step one fair value comparison, and its market capitalization was $721.8 million and its carrying value, including goodwill, was $949.0 million. Ciena applied a 25% control premium to its market capitalization to determine a fair value of $902.2 million. Because step one indicated that Ciena’s fair value was less than its carrying value, Ciena performed the step two analysis. Under the step two analysis, the implied fair value of goodwill requires valuation of a reporting unit’s tangible and intangible assets and liabilities in a manner similar to the allocation of purchase price in a business combination. If the carrying value of a reporting unit’s goodwill exceeds its implied fair value, goodwill is deemed impaired and is written down to the extent of the difference. The implied fair value of the reporting unit’s goodwill was determined to be $0, and, as a result, Ciena recorded a goodwill impairment of $455.7 million, representing the full carrying value of the goodwill. Long-Lived Assets Due to effects of difficult macroeconomic conditions on Ciena’s business, including lengthening sales cycles and slowing deployments resulting in lower demand, Ciena performed an impairment analysis of its long-lived assets during the second quarter of fiscal 2009. Based on Ciena’s estimate of future undiscounted cash flows by asset group, as of April 30, 2009, no impairment was required. Due to the reorganization as a result of the MEN Acquisition, Ciena performed an impairment analysis of its long-lived assets during the second quarter of fiscal 2010. Based on Ciena’s estimate of future undiscounted cash flows by asset group, no impairment was required. Due to the lack of a triggering event, no impairment analysis was performed in fiscal 2011.

GOODWILL AND LONG-LIVED ASSET IMPAIRMENTS

Goodwill

As of October 31, 2010 and 2011, Ciena did not have any goodwill on its Consolidated Balance Sheets.

Prior to the acquisition of the MEN Business, Ciena assessed its goodwill based upon a single reporting unit and tested its single reporting unit’s goodwill for impairment annually on the last business day of fiscal September each year. Testing is required between annual tests if events occur or circumstances change that would, more likely than not, reduce the fair value of the reporting unit below its carrying value. Based on a combination of factors, including macroeconomic conditions and a sustained decline in Ciena’s common stock price and market capitalization below net book value, Ciena conducted an interim impairment assessment of goodwill during the second quarter of fiscal 2009. Ciena performed the step one fair value comparison, and its market capitalization was $721.8 million and its carrying value, including goodwill, was $949.0 million. Ciena applied a 25% control premium to its market capitalization to determine a fair value of $902.2 million. Because step one indicated that Ciena’s fair value was less than its carrying value, Ciena performed the step two analysis. Under the step two analysis, the implied fair value of goodwill requires valuation of a reporting unit’s tangible and intangible assets and liabilities in a manner similar to the allocation of purchase price in a business combination. If the carrying value of a reporting unit’s goodwill exceeds its implied fair value, goodwill is deemed impaired and is written down to the extent of the difference. The implied fair value of the reporting unit’s goodwill was determined to be $0, and, as a result, Ciena recorded a goodwill impairment of $455.7 million, representing the full carrying value of the goodwill.

Long-Lived Assets

Due to effects of difficult macroeconomic conditions on Ciena’s business, including lengthening sales cycles and slowing deployments resulting in lower demand, Ciena performed an impairment analysis of its long-lived assets during the second quarter of fiscal 2009. Based on Ciena’s estimate of future undiscounted cash flows by asset group, as of April 30, 2009, no impairment was required.

Due to the reorganization as a result of the MEN Acquisition, Ciena performed an impairment analysis of its long-lived assets during the second quarter of fiscal 2010. Based on Ciena’s estimate of future undiscounted cash flows by asset group, no impairment was required. Due to the lack of a triggering event, no impairment analysis was performed in fiscal 2011.