Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 01, 2017	Apr. 02, 2016	Apr. 01, 2017	Apr. 02, 2016
Revenues [Abstract]
Subscription	$ 65,780	$ 23,659	$ 120,142	$ 45,835
Support	141,718	160,625	293,196	332,381
Total recurring revenue	207,498	184,284	413,338	378,216
Perpetual license	27,372	39,689	61,751	87,452
Total subscription, support and license revenue	234,870	223,973	475,089	465,668
Professional services	45,170	48,654	91,278	97,976
Total revenue	280,040	272,627	566,367	563,644
Cost of revenue:
Cost of subscription, support and license revenue	43,131	38,613	86,078	75,427
Cost of professional services revenue	38,699	41,578	77,867	84,912
Total cost of revenue	81,830	80,191	163,945	160,339
Gross margin	198,210	192,436	402,422	403,305
Operating expenses:
Sales and marketing	87,777	87,177	178,467	169,606
Research and development	57,710	56,610	115,624	114,279
General and administrative	36,800	33,916	73,495	72,483
Amortization of acquired intangible assets	7,946	8,396	16,013	16,746
Restructuring charges	464	4,579	6,749	41,726
Total operating expenses	190,697	190,678	390,348	414,840
Operating income (loss)	7,513	1,758	12,074	(11,535)
Interest Expense	(11,725)	(4,760)	(22,040)	(11,347)
Interest income and other expense, net	3,156	(567)	2,407	(233)
Loss before income taxes	(1,056)	(3,569)	(7,559)	(23,115)
Provision for income taxes	48	1,604	2,686	5,950
Net loss	$ (1,104)	$ (5,173)	$ (10,245)	$ (29,065)
Earnings(loss) per share—Basic (in USD per share)	$ (0.01)	$ (0.05)	$ (0.09)	$ (0.25)
Earnings(loss) per share—Diluted (in USD per share)	$ (0.01)	$ (0.05)	$ (0.09)	$ (0.25)
Weighted average shares outstanding—Basic (in shares)	115,709	114,563	115,498	114,354
Weighted average shares outstanding—Diluted (in shares)	115,709	114,563	115,498	114,354