Components of Net Periodic Benefit Cost (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Mar. 31, 2012	Apr. 02, 2011	Mar. 31, 2012	Apr. 02, 2011
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 69	$ 73	$ 139	$ 147
Interest cost	109	104	219	207
Expected return on plan assets	(129)	(110)	(257)	(220)
Amortization of prior year service costs	4	4	7	7
Recognized net actuarial loss	78	57	155	114
Net periodic benefit cost	131	128	263	255
Postretirement Medical Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	6	5	11	10
Interest cost	18	16	37	33
Expected return on plan assets	(6)	(6)	(12)	(12)
Amortization of prior year service costs			(1)	(1)
Recognized net actuarial loss	8	2	16	4
Net periodic benefit cost	$ 26	$ 17	$ 51	$ 34