Fair Value Measurements (Tables)

9 Months Ended

Jul. 31, 2011

Fair Value Measurements [Abstract]

Summary of the fair value of assets recorded on a recurring basis

	July 31, 2011
	Level 1		Level 2		Level 3		Total
Assets:
U.S. government obligations	$	50,227	$	—	$	—	$	50,227
Foreign currency forward contracts		—		137		—		137
Embedded redemption feature		—		—		7,600		7,600
Total assets measured at fair value	$	50,227	$	137	$	7,600	$	57,964

Assets are presented on Ciena's Condensed Consolidated Balance Sheet

	July 31, 2011
	Level 1		Level 2		Level 3		Total
Assets:
Prepaid expenses and other	$	—	$	137	$	—	$	137
Long-term investments		50,227		—		—		50,227
Other long-term assets		—		—		7,600		7,600
Total assets measured at fair value	$	50,227	$	137	$	7,600	$	57,964

Reconciliation of changes in Level 3 fair value measurements

	Level 3
Balance at October 31, 2010	$	34,415
Issuances		—
Settlements		(30,195	)
Changes in unrealized gain (loss)		3,380
Transfers into Level 3		—
Transfers out of Level 3		—
Balance at July 31, 2011	$	7,600