Business Segment Information (Details) $ in Thousands	3 Months Ended
	Jan. 02, 2016 USD ($) segment	Dec. 27, 2014 USD ($)
Segment Reporting Information [Line Items]
Number of operating segments | segment	2
Revenue	$ 140,501	$ 142,584
Income from operations	13,601	15,811
Test [Member]
Segment Reporting Information [Line Items]
Revenue	118,810	118,085
Income from operations	10,387	11,976
Sensors [Member]
Segment Reporting Information [Line Items]
Revenue	21,691	24,499
Income from operations	$ 3,214	$ 3,835