Pretax Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2015	Jun. 29, 2014	Jun. 28, 2015	Jun. 29, 2014
Qualified defined benefit pension plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 218	$ 243	$ 435	$ 486
Interest cost	447	488	895	976
Expected return on plan assets	(683)	(659)	(1,367)	(1,319)
Recognized net actuarial losses	400	221	800	442
Amortization of prior service (credits) costs	(98)	21	(195)	42
Total net periodic benefit cost	284	314	568	627
Retiree medical and life insurance plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	5	6	10	11
Interest cost	27	30	55	61
Expected return on plan assets	(37)	(37)	(74)	(73)
Recognized net actuarial losses	11	6	22	12
Amortization of prior service (credits) costs	1	1	2	2
Total net periodic benefit cost	$ 7	$ 6	$ 15	$ 13