Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Dec. 30, 2017	Dec. 31, 2016
Revenues [Abstract]
Subscription	$ 100,008	$ 54,362
Support	131,197	151,478
Total recurring revenue	231,205	205,840
Perpetual license	33,985	34,379
Total subscription, support and license revenue	265,190	240,219
Professional services	41,454	46,108
Total revenue	306,644	286,327
Cost of revenue:
Cost of license and subscription revenue	24,376	20,130
Cost of support revenue	22,200	22,817
Total cost of software revenue	46,576	42,947
Cost of professional services revenue	36,382	39,168
Total cost of revenue	82,958	82,115
Gross margin	223,686	204,212
Operating expenses:
Sales and marketing	99,315	90,690
Research and development	63,969	57,914
General and administrative	35,004	36,695
Amortization of acquired intangible assets	7,821	8,067
Restructuring charges	105	6,285
Total operating expenses	206,214	199,651
Operating income	17,472	4,561
Interest expense	(10,047)	(10,315)
Interest income and other expense, net	(954)	(749)
Income (loss) before income taxes	6,471	(6,503)
Provision (benefit) for income taxes	(7,406)	2,638
Net income (loss)	$ 13,877	$ (9,141)
Earnings(loss) per share—Basic (in USD per share)	$ 0.12	$ (0.08)
Earnings(loss) per share—Diluted (in USD per share)	$ 0.12	$ (0.08)
Weighted average shares outstanding—Basic (in shares)	115,731	115,290
Weighted average shares outstanding—Diluted (in shares)	117,656	115,290