Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jul. 01, 2017	Jul. 02, 2016	Jul. 01, 2017	Jul. 02, 2016
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service costs	$ 90	$ 80	$ 273	$ 239
Interest costs	113	115	336	344
Expected return on plan assets	(219)	(186)	(656)	(560)
Amortization of prior-year service costs	3	3	8	10
Recognized net actuarial loss	101	61	303	182
Net periodic benefit cost	88	73	264	215
Postretirement Medical Plans
Defined Benefit Plan Disclosure [Line Items]
Service costs	3	2	9	8
Interest costs	14	16	42	46
Expected return on plan assets	(13)	(12)	(37)	(34)
Amortization of prior-year service costs	0	(1)	0	(1)
Recognized net actuarial loss	4	2	12	6
Net periodic benefit cost	$ 8	$ 7	$ 26	$ 25