EMPLOYEE STOCK PLANS - Net Share-Based Compensation Expense (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 29, 2018	Jun. 30, 2017	Jun. 29, 2018	Jun. 30, 2017
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation expense	$ 13.3	$ 9.1	$ 34.5	$ 30.7
Income tax benefit for share-based compensation	(3.0)	(2.7)	(7.7)	(9.1)
Cost of revenues - Product
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation expense	0.8	0.7	2.3	2.3
Cost of revenues - Service
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation expense	1.1	1.0	3.1	3.1
Research and development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation expense	1.2	1.3	3.6	3.9
Selling, general and administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation expense	$ 10.2	$ 6.1	$ 25.5	$ 21.4