EMPLOYEE BENEFIT PLANS (Components of Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned	$ 587	$ 530	$ 443
Interest cost	645	713	758
Expected return on plan assets	(1,046)	(1,044)	(906)
Amortization of prior service cost	(6)	(6)	(6)
Amortization of net actuarial loss	6	3	3
Net periodic benefit cost	186	196	292
Less: transfer to regulatory account	147	136	42
Total expense recognized	333	332	334
PBOP Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned	63	61	56
Interest cost	51	63	76
Expected return on plan assets	(137)	(138)	(123)
Amortization of prior service cost	14	14	14
Amortization of net actuarial loss	(33)	(21)	(3)
Net periodic benefit cost	$ (42)	$ (21)	$ 20