Business Combinations (Details) $ / shares in Units, $ in Billions			1 Months Ended		3 Months Ended					12 Months Ended
	Jan. 30, 2018 USD ($)	Jan. 30, 2018 AUD ($) $ / shares	Aug. 31, 2019 USD ($)	Jun. 30, 2019 USD ($)	Oct. 02, 2020 USD ($)	Jul. 03, 2020 USD ($)	Apr. 03, 2020 USD ($)	Jan. 03, 2020 USD ($)	Dec. 28, 2018 USD ($)	Oct. 02, 2020 USD ($) numberOfAcquisitions	Sep. 27, 2019 USD ($) company	Sep. 28, 2018 USD ($)
Business Acquisition [Line Items]
Goodwill acquired										$ 15,700,000	$ 372,300,000
Measurement period adjustment to decrease goodwill								$ (4,800,000)		(1,800,000)	(2,200,000)
Change in fair value of contingent consideration					$ 18,600,000		$ 8,900,000	8,800,000	$ 11,600,000	(300,000)	18,600,000	$ 0
Payment related to contingent consideration										14,000,000.0	1,000,000.0	500,000
IPR&D expensed						$ 20,800,000				0	$ 20,800,000	0
Measurement period adjustment to reduce FV of purchase price consideration					2,600,000			(9,600,000)
Measurement period adjustment to decrease finite-lived intangible assets								$ (5,400,000)
Number of companies acquired | company											4
Goodwill					623,900,000					623,900,000	$ 612,200,000	293,600,000
Business combination, acquisition related costs										26,100,000	23,400,000	6,700,000
Oncology Systems
Business Acquisition [Line Items]
Goodwill acquired										15,700,000	208,000,000.0
Measurement period adjustment to decrease goodwill										(5,600,000)	(2,200,000)
Goodwill					454,700,000					454,700,000	$ 447,900,000	$ 242,100,000
Radiotherapy Equipment Distributer
Business Acquisition [Line Items]
Acquisition purchase price										32,700,000
Cash paid										25,500,000
Contingent consideration					5,800,000					5,800,000
Other consideration										1,400,000
Goodwill acquired										13,100,000
Finite lived intangible assets acquired										12,100,000
Five Other Acquisitions | Oncology Systems
Business Acquisition [Line Items]
Acquisition purchase price										$ 11,500,000
Number of companies acquired | numberOfAcquisitions										5
Cancer Treatment Services International
Business Acquisition [Line Items]
Acquisition purchase price				$ 277,000,000.0
Cash paid				262,800,000
Contingent consideration					8,200,000					$ 8,200,000
Other consideration				6,000,000.0
Decrease to deferred tax liabilities										5,500,000
Measurement period adjustment to decrease goodwill										(5,500,000)
Undiscounted range of contingent consideration payments, low				0
Undiscounted range of contingent consideration payments, high				$ 58,000,000
Revenue projection period for consideration payments				18 months
Additional contingent consideration					3,300,000					3,300,000
Change in fair value of contingent consideration										1,500,000
Finite-lived intangible assets					111,800,000					111,800,000
Goodwill					186,100,000					186,100,000
Endocare and Alicon
Business Acquisition [Line Items]
Acquisition purchase price				$ 210,000,000.0
Cash paid				197,400,000
Contingent consideration					12,600,000					12,600,000
Decrease to deferred tax liabilities										(3,800,000)
Measurement period adjustment to decrease goodwill										3,800,000
Undiscounted range of contingent consideration payments, low				0
Undiscounted range of contingent consideration payments, high				$ 40,000,000
Change in fair value of contingent consideration										8,800,000
Payment related to contingent consideration										39,500,000
Finite-lived intangible assets					64,100,000					64,100,000
Goodwill					118,500,000					118,500,000
Embolics Microspheres Business
Business Acquisition [Line Items]
Cash paid			$ 90,000,000.0
Contingent liability owed to a third party			16,000,000.0
Indemnification assets			$ 16,000,000.0
Finite-lived intangible assets					37,800,000					37,800,000
Goodwill					$ 45,800,000					45,800,000
Privately-held Company
Business Acquisition [Line Items]
Asset acquisition, purchase price						15,200,000
Asset acquisition, holdback amount						3,600,000
Asset acquisition, fair value of contingent consideration						0
Asset acquisition, potential maximum payout of contingent consideration						9,000,000.0
Privately-held Software Company
Business Acquisition [Line Items]
Acquisition purchase price									28,500,000
Goodwill acquired									21,900,000
Finite-lived intangible assets									$ 6,500,000
Sirtex Medical Limited
Business Acquisition [Line Items]
Acquisition purchase price		$ 1.6
Acquisition share price (in AUD per share) | $ / shares		$ 28
Competing bid for Sirtex made by CDH Investments ( in AUD per share) | $ / shares		$ 33.6
Breakup fee from Sirtex	$ 9,000,000.0
Privately-held Software Companies
Business Acquisition [Line Items]
Number of companies acquired | company											2
Fiscal Year 2018 Acquisitions
Business Acquisition [Line Items]
Acquisition purchase price											$ 136,700,000
Cash paid											109,000,000.0
Finite-lived intangible assets											49,900,000
Goodwill											72,100,000
Goodwill deductible for income tax purposes											$ 14,000,000
Siemens Healthineers
Business Acquisition [Line Items]
Business combination, acquisition related costs										$ 10,900,000
Acquisition-related Expenses
Business Acquisition [Line Items]
IPR&D expensed						$ 20,800,000