STOCKHOLDERS' EQUITY AND NONCONTROLLING INTERESTS - Noncontrolling interests (Details) - USD ($) $ in Millions	9 Months Ended
	Jun. 29, 2018	Jun. 30, 2017
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	$ 1,521.9
Balance at end of period	1,501.5
Increase (Decrease) in Temporary Equity [Roll Forward]
Balance at beginning of period		$ 10.3
Net earnings attributable to noncontrolling interests		0.1
Transfer of redeemable noncontrolling interests in MeVis to Varex		(10.3)
Other		(0.1)
Balance at end of period		0.0
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance at beginning of period	4.3	3.7
Net earnings attributable to noncontrolling interests	0.0	0.6
Transfer of redeemable noncontrolling interests in MeVis to Varex	0.0	0.0
Other	0.0	0.0
Balance at end of period	$ 4.3	$ 4.3