REVENUE - Narrative (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Total revenues	[1]	$ 3,487	$ 3,475	$ 9,724	$ 9,282
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	10	31	29
Total revenues		$ 4	$ 2	$ 16	$ 13

[1] Includes excise and gross receipts tax collections of $114 million and $111 million during the three months ended September 30, 2023 and 2022, respectively, and $315 million and $305 million during the nine months ended September 30, 2023 and 2022, respectively.