Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 03, 2021	Mar. 28, 2020	Apr. 03, 2021	Mar. 28, 2020
Defined Benefit Plan Disclosure [Line Items]
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	$ 36	$ (2)	$ 68	$ (5)
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service costs	109	102	217	205
Interest costs	115	133	229	266
Expected return on plan assets	(274)	(273)	(549)	(546)
Amortization of previously deferred service costs	4	4	6	7
Recognized net actuarial loss	185	131	371	262
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	30	(5)	57	(11)
Net periodic benefit cost	139	97	274	194
Postretirement Medical Plans
Defined Benefit Plan Disclosure [Line Items]
Service costs	2	2	5	5
Interest costs	11	14	23	28
Expected return on plan assets	(13)	(15)	(27)	(29)
Amortization of previously deferred service costs	0	0	0	0
Recognized net actuarial loss	8	4	15	7
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	6	3	11	6
Net periodic benefit cost	$ 8	$ 5	$ 16	$ 11