Commitments and Contingencies - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended		3 Months Ended		6 Months Ended
	Dec. 28, 2012 Employee	Sep. 30, 2011	Mar. 29, 2013	Mar. 30, 2012	Mar. 29, 2013	Mar. 30, 2012	Sep. 28, 2012
Commitments and Contingencies [Line Items]
Loan facility to CPTC		$ 165.0			$ 165.3
Varian's participation under the CPTC loan facility		115
Fixed fee committed			10		10
License fee committed			20		20
Environmental cleanup costs, third-party claim costs, project management costs and legal costs			0.2	0.2	0.4	0.4
Receivables of past and future environmental-related expenditures			2.3		2.3		2.6
Liability for actual damages			40		40
Prejudgment interest for damages			13		13
Attorneys' fee			9		9
Court ordered amount					102
Increase liability for actual damages			80		80
Accrued amount of ongoing proceedings			5.4		5.4
Range of reasonably possible loss for the University of Pittsburg matter, Minimum			0		0
Range of reasonably possible loss, maximum			102		102
Number of employees accepted the voluntary retirement program	85
Restructuring charges			2.6		6.7
Payments for restructuring charges			3.8		4.0
Royalties
Commitments and Contingencies [Line Items]
Royalty rate maximum per year			5		5
CERCLA Sites And One Past Facility
Commitments and Contingencies [Line Items]
Estimated environmental remediation costs, minimum			1.9		1.9
Estimated environmental remediation costs, maximum			9.3		9.3
Amount accrued for environmental remediation expense			1.9		1.9
CERCLA Sites And One Past Facility | Minimum
Commitments and Contingencies [Line Items]
Estimated time frames to resolve contingency related to environmental remediation contingencies, years			1		1
CERCLA Sites And One Past Facility | Maximum
Commitments and Contingencies [Line Items]
Estimated time frames to resolve contingency related to environmental remediation contingencies, years			30		30
Other Sites
Commitments and Contingencies [Line Items]
Estimated environmental remediation costs, minimum			6.0		6.0
Estimated environmental remediation costs, maximum			35.3		35.3
Amount accrued for environmental remediation expense			9.7		9.7
Estimated environmental remediation costs, best estimate, undiscounted			$ 12.7		$ 12.7
Discount rate for environmental remediation costs, net of inflation			4.00%		4.00%
Other Sites | Minimum
Commitments and Contingencies [Line Items]
Estimated time frames to resolve contingency related to environmental remediation contingencies, years			1		1
Other Sites | Maximum
Commitments and Contingencies [Line Items]
Estimated time frames to resolve contingency related to environmental remediation contingencies, years			30		30