Business Segment Information (Financial Information By Reportable Segment) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Jul. 02, 2016 USD ($)	Jun. 27, 2015 USD ($)	Jul. 02, 2016 USD ($)	Jun. 27, 2015 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments			2
Revenue	$ 157,700	$ 133,912	$ 435,299	$ 420,451
Total income from operations	9,689	15,427	27,661	48,993
Test [Member]
Segment Reporting Information [Line Items]
Revenue	133,512	109,484	366,119	346,306
Total income from operations	10,683	10,139	22,785	35,256
Sensors [Member]
Segment Reporting Information [Line Items]
Revenue	24,188	24,428	69,180	74,145
Total income from operations	$ (994)	$ 5,288	$ 4,876	$ 13,737