Restructuring and Related Costs (Summary of Restructuring Costs) (Details) - Test & Simulation - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jun. 27, 2020	Jun. 27, 2020
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 2,745	$ 8,883
Cost of sales
Restructuring Cost and Reserve [Line Items]
Restructuring charges	2,192	6,060
Selling and marketing
Restructuring Cost and Reserve [Line Items]
Restructuring charges	686	686
General and administrative
Restructuring Cost and Reserve [Line Items]
Restructuring charges	(183)	2,087
Research and development
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 50	$ 50

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 5.P.3)
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140864-122747

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=115931487&loc=d3e140904-122747

Name:	us-gaap_RestructuringCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration