Components of Net Periodic Benefit Costs (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 25, 2011	Sep. 30, 2012	Sep. 25, 2011
Qualified Defined Benefit Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 264	$ 244	$ 791	$ 731
Interest cost	471	479	1,413	1,438
Expected return on plan assets	(547)	(509)	(1,640)	(1,525)
Recognized net actuarial losses	279	220	837	660
Amortization of prior service cost (credit)	18	21	55	62
Total net periodic benefit cost	485	455	1,456	1,366
Retiree Medical And Life Insurance Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	7	8	21	24
Interest cost	33	41	99	122
Expected return on plan assets	(33)	(35)	(99)	(105)
Recognized net actuarial losses	8	8	24	25
Amortization of prior service cost (credit)	(3)	(4)	(9)	(12)
Total net periodic benefit cost	$ 12	$ 18	$ 36	$ 54