Cover Page - shares	9 Months Ended
	Jul. 03, 2020	Jul. 31, 2020
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jul. 03, 2020
Document Transition Report	false
Entity File Number	1-7598
Entity Registrant Name	VARIAN MEDICAL SYSTEMS, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-2359345
Entity Address, Address Line One	3100 Hansen Way,
Entity Address, City or Town	Palo Alto,
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94304-1038
City Area Code	650
Local Phone Number	493-4000
Title of 12(b) Security	Common Stock, $1 par value
Trading Symbol	VAR
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		90,941,138
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Entity Central Index Key	0000203527
Current Fiscal Year End Date	--10-02