Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Revenues [Abstract]
Subscription	$ 126,712	$ 74,859	$ 339,651	$ 195,001
Support	121,127	140,428	379,007	433,624
Total recurring revenue	247,839	215,287	718,658	628,625
Perpetual license	25,780	32,348	82,604	94,099
Total subscription, support and license revenue	273,619	247,635	801,262	722,724
Professional services	41,158	43,658	128,041	134,936
Total revenue	314,777	291,293	929,303	857,660
Cost of revenue:
Cost of license and subscription revenue	24,010	21,648	71,505	62,333
Cost of support revenue	22,223	23,635	67,453	69,028
Total cost of software revenue	46,233	45,283	138,958	131,361
Cost of professional services revenue	35,323	36,985	109,187	114,852
Total cost of revenue	81,556	82,268	248,145	246,213
Gross margin	233,221	209,025	681,158	611,447
Operating expenses:
Sales and marketing	107,741	93,101	305,386	271,568
Research and development	61,218	59,850	187,381	175,474
General and administrative	33,082	35,294	101,439	108,789
Amortization of acquired intangible assets	7,850	7,973	23,566	23,986
Restructuring and other charges, net	1,627	1,551	1,846	8,300
Total operating expenses	211,518	197,769	619,618	588,117
Operating income	21,703	11,256	61,540	23,330
Interest expense	(10,646)	(10,200)	(31,072)	(32,239)
Interest income and other expense, net	(1,086)	(357)	(2,481)	2,049
Income (loss) before income taxes	9,971	699	27,987	(6,860)
Provision (benefit) for income taxes	(7,026)	1,650	(10,809)	4,336
Net income (loss)	$ 16,997	$ (951)	$ 38,796	$ (11,196)
Earnings(loss) per share—Basic (in USD per share)	$ 0.15	$ (0.01)	$ 0.33	$ (0.10)
Earnings(loss) per share—Diluted (in USD per share)	$ 0.14	$ (0.01)	$ 0.33	$ (0.10)
Weighted average shares outstanding—Basic (in shares)	115,774	115,615	115,915	115,511
Weighted average shares outstanding—Diluted (in shares)	117,500	115,615	117,687	115,511