Capital Assets (Goodwill) (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 29, 2018	Sep. 30, 2017
Goodwill [Roll Forward]
Beginning Balance	$ 369,762	$ 369,700
Adjustment related to finalization of purchase accounting		(64)
Currency translation gain (loss)	(487)	126
Ending Balance	369,275	369,762
Test [Member]
Goodwill [Roll Forward]
Beginning Balance	25,109	25,022
Adjustment related to finalization of purchase accounting		0
Currency translation gain (loss)	(478)	87
Ending Balance	24,631	25,109
Sensors [Member]
Goodwill [Roll Forward]
Beginning Balance	344,653	344,678
Adjustment related to finalization of purchase accounting		(64)
Currency translation gain (loss)	(9)	39
Ending Balance	$ 344,644	$ 344,653

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of foreign currency translation gain (loss) which increases (decreases) an asset representing future economic benefits from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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