Convertible Notes Payable (Details) (USD $) In Thousands, unless otherwise specified	Jul. 31, 2014
Carrying value and estimated current fair value of outstanding convertible notes
Carrying value	$ 1,215,458
Fair Value	1,389,729	[1]
4.0% Convertible Senior Notes due March 15, 2015
Carrying value and estimated current fair value of outstanding convertible notes
Carrying value	187,605	[2]
Fair Value	206,719	[1],[2]
Interest rate on convertible notes	4.00%
0.875% Convertible Senior Notes due June 15, 2017
Carrying value and estimated current fair value of outstanding convertible notes
Carrying value	500,000
Fair Value	494,375	[1]
Interest rate on convertible notes	0.875%
3.75% Convertible Senior Notes due October 15, 2018
Carrying value and estimated current fair value of outstanding convertible notes
Carrying value	350,000
Fair Value	445,813	[1]
Interest rate on convertible notes	3.75%
4.0% Convertible Senior Notes due December 15, 2020
Carrying value and estimated current fair value of outstanding convertible notes
Carrying value	177,853	[3]
Fair Value	$ 242,822	[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.