Convertible Notes Payable (Details) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2013
Carrying value and estimated current fair value of outstanding convertible notes
Carrying value	$ 1,210,907
Fair Value	1,478,540	[1]
4.0% Convertible Senior Notes due March 15, 2015 [Member]
Carrying value and estimated current fair value of outstanding convertible notes
Carrying value	187,775	[2]
Fair Value	240,352	[1],[2]
Interest rate on convertible notes	4.00%
0.875% Convertible Senior Notes due June 15, 2017 [Member]
Carrying value and estimated current fair value of outstanding convertible notes
Carrying value	500,000
Fair Value	491,250	[1]
Interest rate on convertible notes	0.875%
3.75% Convertible Senior Notes due October 15, 2018 [Member]
Carrying value and estimated current fair value of outstanding convertible notes
Carrying value	350,000
Fair Value	482,563	[1]
Interest rate on convertible notes	3.75%
4.0% Convertible Senior Notes due December 15, 2020 [Member]
Carrying value and estimated current fair value of outstanding convertible notes
Carrying value	173,132	[3]
Fair Value	$ 264,375	[1],[3]
Interest rate on convertible notes	4.00%

[1] The convertible notes were categorized as Level 2 in the fair value hierarchy. Ciena estimated the fair value of its outstanding convertible notes using a market approach based upon observable inputs, such as current market transactions involving comparable securities.

[2] Includes unamortized bond premium related to embedded redemption feature.

[3] Includes unamortized discount and accretion of principal.