Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 30, 2018	Apr. 30, 2017	Apr. 30, 2018	Apr. 30, 2017
Revenue:
Products	$ 604,226	$ 584,630	$ 1,129,835	$ 1,091,623
Services	125,752	122,392	246,278	236,896
Total revenue	729,978	707,022	1,376,113	1,328,519
Cost of goods sold:
Products	372,568	327,295	685,688	614,106
Services	64,103	61,487	125,353	122,388
Total cost of goods sold	436,671	388,782	811,041	736,494
Gross profit	293,307	318,240	565,072	592,025
Operating expenses:
Research and development	116,924	121,623	235,448	238,492
Selling and marketing	97,359	88,551	185,874	173,553
General and administrative	38,976	34,990	77,382	70,854
Amortization of intangible assets	3,623	10,980	7,246	25,531
Significant asset impairments and restructuring costs	4,359	4,276	10,320	6,671
Total operating expenses	261,241	260,420	516,270	515,101
Income from operations	32,066	57,820	48,802	76,924
Interest and other income (loss), net	1,296	(2,918)	2,871	(2,548)
Interest expense	(13,031)	(13,308)	(26,765)	(28,511)
Income before income taxes	20,331	41,594	24,908	45,865
Provision for income taxes	6,475	3,568	484,415	3,978
Net income (loss)	$ 13,856	$ 38,026	$ (459,507)	$ 41,887
Basic net income (loss) per common share (in dollars per share)	$ 0.10	$ 0.27	$ (3.19)	$ 0.30
Diluted net income (loss) per potential common share (in dollars per share)	$ 0.09	$ 0.25	$ (3.19)	$ 0.29
Weighted average basic common shares outstanding (in shares)	143,975	141,743	143,948	141,223
Weighted average dilutive potential common shares outstanding (in shares)	147,973	165,273	143,948	147,842