Revenue (Pre-contract Costs) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019	Sep. 28, 2019
Revenue from Contract with Customer [Abstract]
Capitalized pre-contract costs	$ 3,965		$ 3,965		$ 4,297
Capitalized pre-contract costs, related expense	$ 1,017	$ 1,747	$ 3,857	$ 5,616

Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054

Name:	us-gaap_CapitalizedContractCostNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant