NET INCOME (LOSS) PER SHARE - (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Oct. 01, 2021	Oct. 02, 2020	Sep. 27, 2019
Earnings Per Share [Abstract]
Net income (loss) attributable to Varex	$ 17.4	$ (57.9)	$ 15.5
Weighted average shares outstanding - basic (in shares)	39.3	38.8	38.2
Dilutive effect of convertible senior notes (in shares)	0.6	0.0	0.0
Dilutive effect of common share-based awards and other (in shares)	0.4	0.0	0.4
Diluted (in shares)	40.3	38.8	38.6
Net earnings per share attributable to Varex - basic (in USD per share)	$ 0.44	$ (1.49)	$ 0.41
Net earnings per share attributable to Varex - diluted (in USD per share)	$ 0.43	$ (1.49)	$ 0.40
Anti-dilutive employee shared based awards, excluded (in shares)	2.8	3.5	1.9