Fair Value Measurements Activity Between Levels of the Fair Value Hierarchy, Assets (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Dec. 29, 2013	Dec. 30, 2012
Auction Rate Securities [Member]
Activity for Marketable Securities Classified Within Level 3 of the Valuation Hierarchy [Roll Forward]
Beginning balance of Level 3	$ 83	$ 118
Total realized and unrealized gains or losses [Abstract]
Included in investment income, net	0	0
Included in other comprehensive income	0	1
Purchases	0	0
Sales	0	0
Settlements	0	(34)
Transfers into Level 3	0	0
Ending balance of Level 3	83	85
Other Marketable Securities [Member]
Activity for Marketable Securities Classified Within Level 3 of the Valuation Hierarchy [Roll Forward]
Beginning balance of Level 3	239	203
Total realized and unrealized gains or losses [Abstract]
Included in investment income, net	2	2
Included in other comprehensive income	(1)	2
Purchases	23	41
Sales	(9)	(1)
Settlements	(8)	(19)
Transfers into Level 3	0	14
Ending balance of Level 3	$ 246	$ 242