Pension and Postretirement Benefit Plans - Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Pension Plan [Member] | U.S. [Member] | Qualified [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost	157	150	315	301
Expected return on plan assets	(223)	(261)	(445)	(524)
Amortization of:
Actuarial losses	37	30	74	60
Prior service costs/(credits)	(1)	0	(2)	1
Curtailments	0	7	0	9
Settlements	2	25	2	45
Special termination benefits	1	0	1	0
Defined benefit plan, net periodic benefit cost	(27)	(49)	(55)	(107)
Pension Plan [Member] | International [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	31	34	63	71
Interest cost	54	55	109	109
Expected return on plan assets	(80)	(93)	(160)	(185)
Amortization of:
Actuarial losses	20	26	41	52
Prior service costs/(credits)	(1)	(1)	(2)	(2)
Curtailments	0	0	0	0
Settlements	0	0	0	0
Special termination benefits	0	0	0	0
Defined benefit plan, net periodic benefit cost	25	21	51	44
Supplemental Employee Retirement Plan [Member] | U.S. [Member] | Non-Qualified [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	0	0	0	0
Interest cost	12	14	25	26
Expected return on plan assets	0	0	0	0
Amortization of:
Actuarial losses	2	3	5	7
Prior service costs/(credits)	0	0	0	0
Curtailments	0	0	0	0
Settlements	0	5	0	21
Special termination benefits	3	0	9	0
Defined benefit plan, net periodic benefit cost	17	21	37	55
Postretirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	9	10	19	20
Interest cost	19	18	38	36
Expected return on plan assets	(8)	(9)	(16)	(18)
Amortization of:
Actuarial losses	1	2	2	4
Prior service costs/(credits)	(45)	(45)	(89)	(90)
Curtailments	0	(7)	0	(14)
Settlements	0	0	0	0
Special termination benefits	1	0	1	0
Defined benefit plan, net periodic benefit cost	$ (23)	$ (32)	$ (46)	$ (63)