Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Disaggregation Of Revenue [Line Items]
Revenue	$ 351,721	$ 295,486	$ 1,067,434	$ 920,626
Total recurring revenue
Disaggregation Of Revenue [Line Items]
Revenue	310,621	244,192	931,852	734,815
Perpetual license
Disaggregation Of Revenue [Line Items]
Revenue	6,773	9,213	23,988	61,354
Professional services
Disaggregation Of Revenue [Line Items]
Revenue	$ 34,327	$ 42,081	$ 111,594	$ 124,457

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130543-203045

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=118956577&loc=SL49130545-203045

Name:	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration