POSTRETIREMENT BENEFIT PLANS - Schedule of Pretax Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Qualified defined benefit pension plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 26	$ 129	$ 51	$ 258
Interest cost	384	451	769	903
Expected return on plan assets	(566)	(575)	(1,132)	(1,150)
Recognized net actuarial losses	212	351	424	702
Amortization of prior service credits	(85)	(83)	(171)	(167)
Total net periodic benefit (income) cost	(29)	273	(59)	546
Retiree medical and life insurance plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	4	3	7	7
Interest cost	17	24	35	48
Expected return on plan assets	(32)	(27)	(64)	(55)
Recognized net actuarial losses	(1)	0	(2)	1
Amortization of prior service credits	9	11	19	21
Total net periodic benefit (income) cost	$ (3)	$ 11	$ (5)	$ 22