Capital Assets (Goodwill) (Details) $ in Thousands	6 Months Ended
	Apr. 01, 2017 USD ($)
Goodwill [Roll Forward]
Goodwill, Beginning Balance	$ 369,700
Currency translation gain (loss)	(476)
Goodwill, Ending Balance	369,224
Test [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	25,022
Currency translation gain (loss)	(440)
Goodwill, Ending Balance	24,582
Sensors [Member]
Goodwill [Roll Forward]
Goodwill, Beginning Balance	344,678
Currency translation gain (loss)	(36)
Goodwill, Ending Balance	$ 344,642