Segment and Entity Wide Disclosures (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Apr. 30, 2009	Oct. 31, 2011	Oct. 31, 2010	Oct. 31, 2009
Revenue:
Revenue		$ 1,741,970	$ 1,236,636	$ 652,629
Segment profit (loss) and the reconciliation to consolidated net income (loss)
Segment profit (loss)		329,284	169,875	94,511
Selling and marketing		251,990	193,515	134,527
General and administrative		126,242	102,692	47,509
Acquisition and integration costs		42,088	101,379	0
Amortization of intangible assets		69,665	99,401	24,826
Restructuring costs		5,781	8,514	11,207
Goodwill impairment	455,700	0	0	455,673
Change in fair value of contingent consideration		(3,289)	(13,807)	0
Interest expense and other income (loss), net		(31,904)	(14,702)	2,081
Gain (loss) on cost method investments		7,249	0	(5,328)
Gain on extinguishment of debt		0	4,948	0
Provision (benefit) for income taxes		7,673	1,941	(1,324)
Net loss		(195,521)	(333,514)	(581,154)
Packet-Optical Transport [Member]
Revenue:
Revenue		1,121,811	705,551	299,088
Segment profit (loss) and the reconciliation to consolidated net income (loss)
Segment profit (loss)		191,727	69,319	21,535
Packet-Optical Switching [Member]
Revenue:
Revenue		148,395	112,058	165,705
Segment profit (loss) and the reconciliation to consolidated net income (loss)
Segment profit (loss)		49,286	15,662	60,302
Carrier-Ethernet Solutions [Member]
Revenue:
Revenue		127,868	179,083	75,125
Segment profit (loss) and the reconciliation to consolidated net income (loss)
Segment profit (loss)		10,849	28,742	(9,575)
Software and Services [Member]
Revenue:
Revenue		343,896	239,944	112,711
Segment profit (loss) and the reconciliation to consolidated net income (loss)
Segment profit (loss)		$ 77,422	$ 56,152	$ 22,249