Net Periodic Benefit Cost (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 28, 2014	Jun. 29, 2013	Jun. 28, 2014	Jun. 29, 2013
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service costs	$ 71	$ 86	$ 213	$ 258
Interest costs	121	109	365	326
Expected return on plan assets	(161)	(151)	(484)	(452)
Amortization of prior-year service costs	4	2	11	7
Recognized net actuarial loss/(gain)	37	105	110	313
Net periodic benefit cost	72	151	215	452
Postretirement Medical Plans
Defined Benefit Plan Disclosure [Line Items]
Service costs	3	4	8	13
Interest costs	16	17	49	50
Expected return on plan assets	(9)	(8)	(27)	(23)
Amortization of prior-year service costs	0	(1)	(1)	(2)
Recognized net actuarial loss/(gain)	(2)	10	(6)	30
Net periodic benefit cost	$ 8	$ 22	$ 23	$ 68