GOODWILL AND INTANGIBLE ASSETS - Activity of Goodwill by Reportable Operating Segment (Details) $ in Millions	9 Months Ended
Jul. 03, 2020 USD ($)	Sep. 27, 2019 USD ($)
Goodwill [Roll Forward]
Beginning balance	$ 612.2
Business combination	2.6
Measurement period adjustments to business combinations in prior year	(1.8)
Foreign currency translation adjustments	(5.6)
Ending balance	607.4
Oncology Systems
Goodwill [Roll Forward]
Beginning balance	447.9
Business combination	2.6
Measurement period adjustments to business combinations in prior year	(5.6)
Foreign currency translation adjustments	(4.3)
Ending balance	440.6
Other
Goodwill [Roll Forward]
Beginning balance	164.3
Business combination	0.0
Measurement period adjustments to business combinations in prior year	3.8
Foreign currency translation adjustments	(1.3)
Ending balance	166.8
Proton Solutions
Goodwill [Roll Forward]
Accumulated impairment charges	$ 50.5	$ 50.5

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 increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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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 accumulated impairment loss for 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 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.

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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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