REVENUE - Narrative (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Revenues	[1]	$ 3,006	$ 2,818	$ 6,237	$ 5,807
Incremental decrease to uncollectible expense due to Covid-19				52
Deferred Regulatory Assets
Disaggregation of Revenue [Line Items]
Incremental decrease to uncollectible expense due to Covid-19				27
Other Non-Customer Revenue | Derivative revenue
Disaggregation of Revenue [Line Items]
Late payment charges		10	9	21	19
Revenues		$ 6	$ 2	$ 12	$ 11

[1] Includes excise and gross receipts tax collections of $92 million and $91 million during the three months ended June 30, 2023 and 2022, respectively, and $201 million and $194 million during the six months ended June 30, 2023 and 2022, respectively.