POSTRETIREMENT BENEFIT PLANS - Schedule of Pretax Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 29, 2020	Mar. 31, 2019
Qualified defined benefit pension plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 25	$ 129
Interest cost	385	452
Expected return on plan assets	(566)	(575)
Recognized net actuarial losses	212	351
Amortization of prior service credits	(86)	(84)
Total net periodic benefit (income) cost	(30)	273
Retiree medical and life insurance plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	3	4
Interest cost	18	24
Expected return on plan assets	(32)	(28)
Recognized net actuarial losses	(1)	1
Amortization of prior service credits	10	10
Total net periodic benefit (income) cost	$ (2)	$ 11