Components of Pretax Net Periodic Benefit Costs (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 24, 2012	Jun. 30, 2013	Jun. 24, 2012
Qualified defined benefit pension plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 285	$ 263	$ 571	$ 527
Interest cost	450	471	900	942
Expected return on plan assets	(621)	(546)	(1,243)	(1,093)
Recognized net actuarial losses	353	279	706	558
Amortization of prior service cost (credit)	20	19	40	37
Total net periodic benefit cost	487	486	974	971
Retiree medical and life insurance plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	7	7	14	14
Interest cost	29	33	58	66
Expected return on plan assets	(37)	(33)	(73)	(66)
Recognized net actuarial losses	11	8	22	16
Amortization of prior service cost (credit)	(4)	(3)	(9)	(6)
Total net periodic benefit cost	$ 6	$ 12	$ 12	$ 24