POSTRETIREMENT BENEFIT PLANS - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 28, 2021	Mar. 29, 2020
Defined Benefit Plan Disclosure [Line Items]
Recognition of previously deferred postretirement benefit plan amounts, before tax	$ 178,000,000	$ 140,000,000
Recognition of previously deferred postretirement benefit plan amounts, net of tax	140,000,000	110,000,000
Retiree medical and life insurance plans
Defined Benefit Plan Disclosure [Line Items]
Recognition of previously deferred postretirement benefit plan amounts, before tax	4,000,000	5,000,000
Qualified defined benefit pension plans
Defined Benefit Plan Disclosure [Line Items]
Material contributions to qualified defined benefit pension plans	$ 0	$ 0