Restructuring and Impairment Charges, Restructuring Accrual Activity (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 26, 2015
Restructuring Accrual [Roll Forward]
Beginning balance	$ 13	$ 10
Acquisition	13
Charges	24	32	$ 13
Non-cash asset impairment	(2)	(3)	(2)
Cash payments	(29)	(26)
Ending balance	19	13	10
Employee Severance and Benefits [Member]
Restructuring Accrual [Roll Forward]
Beginning balance	7	2
Acquisition	13
Charges	18	23
Non-cash asset impairment	0	0
Cash payments	(24)	(18)
Ending balance	14	7	2
Facility Exit [Member]
Restructuring Accrual [Roll Forward]
Beginning balance	6	8
Acquisition	0
Charges	4	6
Non-cash asset impairment	0	0
Cash payments	(5)	(8)
Ending balance	5	6	8
Non-Cash Impairment Charges [Member]
Restructuring Accrual [Roll Forward]
Beginning balance	0	0
Acquisition	0
Charges	2	3
Non-cash asset impairment	(2)	(3)
Cash payments	0	0
Ending balance	$ 0	$ 0	$ 0