Summary of Significant Accounting Policies (Narrative) (Details)	12 Months Ended
	Sep. 28, 2019 USD ($) reporting_unit	Sep. 29, 2018 USD ($)	Sep. 30, 2017 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Capitalization of software development costs	$ 8,295,000	$ 5,167,000	$ 2,900,000
Foreign currency transaction gain (loss), before tax	(200,000)	104,000	(2,499,000)
Amortization expense on capitalized computer software	176,000	30,000	892,000
Goodwill impairment	0	0
Impairment of intangible assets	$ 0	0
Number of reporting units | reporting_unit	4
Goodwill	$ 429,039,000	369,275,000	$ 369,762,000
Foreign exchange contracts with credit-risk related contingent features	$ 0	0
Minimum
Summary Of Significant Accounting Policies [Line Items]
Percent fair value is less than carrying amount	50.00%
Test & Simulation Excluding E2M
Summary Of Significant Accounting Policies [Line Items]
Goodwill	$ 25,993,000
E2M Technologies B.V.
Summary Of Significant Accounting Policies [Line Items]
Goodwill	35,160,000
Temposonics
Summary Of Significant Accounting Policies [Line Items]
Goodwill	1,416,000
PCB Group, Inc
Summary Of Significant Accounting Policies [Line Items]
Goodwill	366,470,000
Research And Development
Summary Of Significant Accounting Policies [Line Items]
Capitalization of software development costs	$ 5,883,000	$ 1,803,000