EMPLOYEE STOCK PLANS - Net Share-Based Compensation Expense (Detail) - USD ($) $ in Millions	3 Months Ended
	Dec. 30, 2016	Jan. 01, 2016
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation expense	$ 11.5	$ 11.3
Income tax benefit for share-based compensation	(3.5)	(3.5)
Cost of revenues - Product
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation expense	1.0	1.0
Cost of revenues - Service
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation expense	1.0	1.0
Research and development
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation expense	1.5	1.6
Selling, general and administrative
Employee Service Share Based Compensation Allocation Of Recognized Period Costs [Line Items]
Total share-based compensation expense	$ 8.0	$ 7.7