Quarterly Financial Data - Schedule of Quarterly Financial Data (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended							9 Months Ended	12 Months Ended
	Oct. 02, 2015	Apr. 03, 2015	Jan. 02, 2015	Sep. 26, 2014	Jun. 27, 2014	Mar. 28, 2014	Dec. 27, 2013	Jul. 03, 2015	Oct. 02, 2015	Sep. 26, 2014	Sep. 27, 2013
Loss Contingencies [Line Items]
Total revenues	$ 817,800	$ 759,400	$ 737,900	$ 812,100	$ 747,700	$ 778,500	$ 711,500	$ 784,000	$ 3,099,111	$ 3,049,800	$ 2,942,897
Gross margin	318,200	322,500	327,000	340,100	323,700	328,300	309,600	315,000	1,282,692	1,301,675	1,249,687
Net earnings attributable to Varian	$ 98,700	$ 106,000	$ 93,300	$ 105,900	$ 107,100	$ 92,700	$ 98,000	$ 113,500	$ 411,485	$ 403,703	$ 438,248
Net earnings per share – basic: (in dollars per share)	$ 1.00	$ 1.06	$ 0.93	$ 1.04	$ 1.03	$ 0.89	$ 0.92	$ 1.14	$ 4.13	$ 3.88	$ 4.04
Net earnings per share – diluted: (in dollars per share)	$ 0.99	$ 1.05	$ 0.92	$ 1.02	$ 1.02	$ 0.88	$ 0.91	$ 1.13	$ 4.09	$ 3.83	$ 3.98
University of Pittsburgh
Loss Contingencies [Line Items]
Losses accrued						$ 25,100	$ 5,000