EMPLOYEE BENEFIT PLANS (Reconciliation of Changes in Plan Assets Benefit Obligations and Funded Status) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Funded Status:
Noncurrent liability	$ (476)	$ (231)
Pension Plan
Change in plan assets:
Fair value of plan assets at beginning of year	16,369	21,895
Actual return on plan assets	1,518	(4,916)
Company contributions	336	339
Benefits and expenses paid	(1,012)	(949)
Fair value of plan assets at end of year	17,211	16,369	$ 21,895
Change in benefit obligation:
Benefit obligation at beginning of year	16,608	22,759
Service cost for benefits earned	379	575	587
Interest cost	913	692	645
Actuarial loss/(gain)	809	(6,471)
Plan amendments	0	0
Benefits and expenses paid	(1,012)	(947)
Benefit obligation at end of year	17,697	16,608	22,759
Funded Status:
Current liability	(9)	(8)
Noncurrent liability	(477)	(231)
Net (liability) asset at end of year	(486)	(239)
Accumulated benefit obligation	16,300	15,400
PBOP Plans
Change in plan assets:
Fair value of plan assets at beginning of year	2,336	3,102
Actual return on plan assets	260	(693)
Company contributions	5	26
Plan participant contribution	81	81
Benefits and expenses paid	(183)	(180)
Fair value of plan assets at end of year	2,499	2,336	3,102
Change in benefit obligation:
Benefit obligation at beginning of year	1,339	1,766
Service cost for benefits earned	38	62	63
Interest cost	73	53	51
Actuarial loss/(gain)	8	(486)
Benefits and expenses paid	(165)	(162)
Federal subsidy on benefits paid	3	3
Plan participant contributions	81	81
VSP related termination benefits	0	22
Benefit obligation at end of year	1,377	1,339	$ 1,766
Funded Status:
Noncurrent asset	1,122	997
Noncurrent liability	0	0
Net (liability) asset at end of year	1,122	997
PBOP Plans | Postretirement Life Insurance Plan
Change in plan assets:
Fair value of plan assets at beginning of year	266
Fair value of plan assets at end of year	292	266
Change in benefit obligation:
Benefit obligation at beginning of year	259
Benefit obligation at end of year	$ 275	$ 259