Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 01, 2017	Apr. 02, 2016	Apr. 01, 2017	Apr. 02, 2016
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service costs	$ 92	$ 79	$ 183	$ 159
Interest costs	111	114	223	229
Expected return on plan assets	(218)	(186)	(437)	(374)
Amortization of prior-year service costs	2	4	5	7
Recognized net actuarial loss	101	60	202	121
Net periodic benefit cost	88	71	176	142
Postretirement Medical Plans
Defined Benefit Plan Disclosure [Line Items]
Service costs	3	3	6	6
Interest costs	14	15	28	30
Expected return on plan assets	(12)	(11)	(24)	(22)
Amortization of prior-year service costs	0	0	0	0
Recognized net actuarial loss	4	2	8	4
Net periodic benefit cost	$ 9	$ 9	$ 18	$ 18