EMPLOYEE STOCK PLANS Share-based Compensation Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 29, 2017	Dec. 30, 2016
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	$ 2.1	$ 2.3
Cost of revenues
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	0.2	0.2
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	0.4	0.4
Selling, general and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense	$ 1.5	1.7
Varian | General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Allocated share-based compensation expense		$ 0.8