EARNINGS PER SHARE - Computation of Net Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Dec. 30, 2016	Jan. 01, 2016
Earnings Per Share [Abstract]
Net earnings attributable to Varian	$ 20.4	$ 89.0
Weighted average shares outstanding - basic (in shares)	93.5	97.2
Dilutive effect of potential common shares (in shares)	0.7	0.6
Weighted average shares outstanding - diluted (in shares)	94.2	97.8
Net earnings per share - basic (in dollars per share)	$ 0.22	$ 0.92
Net earnings per share - diluted (in dollars per share)	$ 0.22	$ 0.91
Anti-dilutive employee shared based awards, excluded (in shares)	0.6	1.2