EMPLOYEE BENEFIT PLANS - Benefit Obligations, Fair Value of Plan Assets and Funded Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Pension Benefits
Change in Benefit Obligation
Benefit obligation at beginning of period	$ 21,073	$ 22,626
Service cost	0	0	$ 0
Interest cost	611	582	700
Actuarial (gain)/loss	(4,599)	(851)
Benefits paid, including lump sums and annuities	(1,274)	(1,284)
Participant contributions	0	0
Benefit obligation at end of period	15,811	21,073	22,626
Change in Fair Value of Plan Assets
Fair value of plan assets at beginning of period	19,502	16,541
Actual gain/(loss) on plan assets	(2,517)	2,732
Employer contributions	10	1,513
Participant contributions	0	0
Benefits paid, including lump sums and annuities	(1,274)	(1,284)
Fair value of plan assets at end of period	15,721	19,502	16,541
Funded Status of Plan
Funded status at end of period	(90)	(1,571)
Other Postretirement and Postemployment Benefits
Change in Benefit Obligation
Benefit obligation at beginning of period	4,605	4,766
Service cost	70	86	96
Interest cost	128	117	120
Actuarial (gain)/loss	(710)	23
Benefits paid, including lump sums and annuities	(447)	(405)
Participant contributions	18	18
Benefit obligation at end of period	3,664	4,605	4,766
Change in Fair Value of Plan Assets
Fair value of plan assets at beginning of period	357	496
Actual gain/(loss) on plan assets	(73)	57
Employer contributions	216	192
Participant contributions	18	18
Benefits paid, including lump sums and annuities	(447)	(406)
Fair value of plan assets at end of period	71	357	$ 496
Funded Status of Plan
Funded status at end of period	$ (3,593)	$ (4,248)