Credit Facilities - Additional Information (Detail) In Millions, unless otherwise specified	9 Months Ended						9 Months Ended					9 Months Ended
	Jun. 28, 2013 Two Thousand Twelve Credit Facility USD ($)	Jun. 28, 2013 Two Thousand Twelve Credit Facility Minimum	Jun. 28, 2013 Two Thousand Twelve Credit Facility Maximum	Jun. 28, 2013 Two Thousand Twelve Credit Facility Interest Accrued Description One	Jun. 28, 2013 Two Thousand Twelve Credit Facility Interest Accrued Description One Minimum	Jun. 28, 2013 Two Thousand Twelve Credit Facility Interest Accrued Description One Maximum	Jun. 28, 2013 Two Thousand Twelve Credit Facility Interest Accrued Description Two	Jun. 28, 2013 Two Thousand Twelve Credit Facility Interest Accrued Description Two Minimum	Jun. 28, 2013 Two Thousand Twelve Credit Facility Interest Accrued Description Two Maximum	Jun. 28, 2013 Two Thousand Twelve Credit Facility Letter of Credit USD ($)	Jun. 28, 2013 Two Thousand Twelve Credit Facility Swingline Loans USD ($)	Jun. 28, 2013 Sumitomo Credit Facility USD ($)	Jun. 28, 2013 Sumitomo Credit Facility JPY (¥)
Line Of Credit Facility [Line Items]
Date of credit agreement	Apr. 27, 2012
Loan facility, maximum borrowing capacity	$ 300									$ 50	$ 25		¥ 3,000
Aggeragte commitments of credit facility	200
Percentage of Varian Medical Systems Nederland Holdings B.V. voting shares pledged	65.00%
Line of credit, interest rate					1.25%	1.50%
Line of credit, description of interest rate calculation				Based on a Eurodollar rate (as defined in the credit agreement), plus a margin of 1.25% to 1.5% based on a leverage ratio involving funded indebtedness and earnings before interest, taxes and depreciation and amortization (“EBITDA” )			The Eurodollar rate plus 1%, plus a margin of 0.25% to 0.5% based on the same leverage ratio, depending on instructions from the Company
Margin added if base rate is based on federal funds rate							0.50%
Line of credit, interest rate calculation (base rate margin)								0.25%	0.50%
Commitment fees at an annual rate		0.25%	0.30%
Line of credit, commitment fee	0.25% to 0.30% based on the same leverage ratio
Line of credit, amount outstanding	$ 150.0											$ 18.1	¥ 1,800.0
Credit facility weighted average interest rate	1.44%
Sumitomo credit facility expiration date												Apr. 05, 2014	Apr. 05, 2014
Credit facility accrued interest rate per annum												0.50%	0.50%
Line of credit, interest rate												0.65%	0.65%