Restructuring Costs (Details) $ in Thousands	3 Months Ended			9 Months Ended
	Jul. 31, 2015 USD ($)	Jan. 31, 2015 USD ($) employee	Jul. 31, 2014 USD ($)	Jul. 31, 2015 USD ($)		Jul. 31, 2014 USD ($)
Activity and balance of the restructuring liability accounts
Balance at beginning of period		$ 1,315		$ 1,315		$ 2,016
Additional liability recorded	$ 192		$ 63	8,260		178
Cash payments				(8,118)		(477)
Balance at end of period	1,457		1,717	1,457		1,717
Current restructuring liabilities	1,089		653	1,089		653
Non-current restructuring liabilities	368		1,064	368		1,064
Workforce reduction
Activity and balance of the restructuring liability accounts
Balance at beginning of period		181		181		80
Additional liability recorded		$ 8,100		8,260	[1]	169
Cash payments				(7,748)		(208)
Balance at end of period	693		41	693		41
Current restructuring liabilities	693		41	693		41
Non-current restructuring liabilities	0		0	0		0
Workforce deduction | employee		125
Consolidation of excess facilities
Activity and balance of the restructuring liability accounts
Balance at beginning of period		$ 1,134		1,134		1,936
Additional liability recorded				0		9
Cash payments				(370)		(269)
Balance at end of period	764		1,676	764		1,676
Current restructuring liabilities	396		612	396		612
Non-current restructuring liabilities	$ 368		$ 1,064	$ 368		$ 1,064

[1] During the fiscal quarter ended January 31, 2015, Ciena recorded a charge of $8.1 million of severance and other employee-related costs associated with a global workforce reduction of approximately 125 employees.