POSTRETIREMENT BENEFIT PLANS - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 25, 2018	Mar. 26, 2017
Defined Benefit Plan Disclosure [Line Items]
Recognition of previously deferred postretirement benefit plan amounts, before tax	$ 382	$ 312
Recognition of previously deferred postretirement benefit plan amounts, net of tax	300	202
Retiree medical and life insurance plans
Defined Benefit Plan Disclosure [Line Items]
Recognition of previously deferred postretirement benefit plan amounts, before tax	14	14
Qualified defined benefit pension plans
Defined Benefit Plan Disclosure [Line Items]
Material contributions to qualified defined benefit pension plans	1,500	$ 0
Expected future employer contributions	$ 3,500