Business Acquisition (Purchase Price Schedule) (Details) - USD ($) $ in Thousands		12 Months Ended
	Jul. 05, 2016	Sep. 29, 2018	Sep. 30, 2017	Oct. 01, 2016
Business Acquisition [Line Items]
Total purchase price consideration, net of cash acquired		$ 0	$ 853	$ 580,920
PCB Group, Inc [Member]
Business Acquisition [Line Items]
Consideration paid to PCB shareholders and employees1	$ 580,000
Consideration for PCB closing cash	11,612
Deferred endowment consideration2	1,000
Net preacquisition earn-out	(141)
Net working capital adjustment3	(147)
Cash acquired	(10,551)
Total purchase price consideration, net of cash acquired	581,773
Employees [Member] | PCB Group, Inc [Member]
Business Acquisition [Line Items]
Consideration paid to PCB shareholders and employees1	$ 10,000