Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended
	Jan. 02, 2016	Dec. 27, 2014
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service costs	$ 80	$ 83
Interest costs	115	131
Expected return on plan assets	(188)	(178)
Amortization of prior-year service costs	3	4
Recognized net actuarial loss/(gain)	61	62
Net periodic benefit cost	71	102
Postretirement Medical Plans
Defined Benefit Plan Disclosure [Line Items]
Service costs	3	4
Interest costs	15	17
Expected return on plan assets	(11)	(10)
Amortization of prior-year service costs	0	0
Recognized net actuarial loss/(gain)	2	3
Net periodic benefit cost	$ 9	$ 14