SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Components of Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned	$ 144	$ 146	$ 288	$ 293
Interest cost	173	162	346	323
Expected return on plan assets	(298)	(262)	(595)	(523)
Amortization of prior service cost	(1)	(2)	(2)	(3)
Amortization of net actuarial loss	1	2	1	3
Net periodic benefit cost	19	46	38	93
Regulatory account transfer	64	37	127	74
Net periodic benefit cost	83	83	165	167
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost for benefits earned	16	16	31	32
Interest cost	14	13	27	26
Expected return on plan assets	(33)	(35)	(65)	(70)
Amortization of prior service cost	1	3	3	7
Amortization of net actuarial loss	(10)	(8)	(20)	(16)
Net periodic benefit cost	(12)	(11)	(24)	(21)
Regulatory account transfer	0	0	0	0
Net periodic benefit cost	$ (12)	$ (11)	$ (24)	$ (21)