OTHER FINANCIAL INFORMATION - Unbilled Receivables and Deferred Revenues from Contracts with Customers (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 28, 2019	Jun. 29, 2018	Jun. 28, 2019	Jun. 29, 2018	Sep. 28, 2018
Other Financial Information [Abstract]
Unbilled receivables - current	$ 324.8		$ 324.8		$ 362.8
Unbilled receivables - long-term (1)	63.2		63.2		36.3
Deferred revenues - current	(749.7)		(749.7)		(729.7)	[1]
Deferred revenues - long-term (2)	(73.5)		(73.5)		(38.6)
Total net unbilled receivables (deferred revenues)	(435.2)		(435.2)		$ (369.2)
Recognized revenue included in deferred revenue balance	$ 207.2	$ 66.5	$ 545.0	$ 367.0

[1] The condensed consolidated balance sheet as of September 28, 2018, was derived from audited financial statements as of that date, but does not include all disclosures required by accounting principles generally accepted in the United States of America.