REVENUE - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Total revenues	[1]	$ 3,729	$ 3,487	$ 10,296	$ 9,724
Operating Segments
Disaggregation of Revenue [Line Items]
Total revenues		3,744	3,500	10,338	9,764
Operating Segments | Distribution
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		1,798	1,777	5,173	5,184
Total revenues		1,817	1,795	5,232	5,239
Operating Segments | Distribution | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		2	7	4	20
Operating Segments | Distribution | Other revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		23	23	63	69
Operating Segments | Distribution | Other revenue unrelated to contracts with customers
Disaggregation of Revenue [Line Items]
Total revenues		19	18	59	55
Operating Segments | Integrated
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		1,437	1,259	3,694	3,223
Total revenues		1,452	1,266	3,725	3,250
Operating Segments | Integrated | Transmission
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		86	74	283	224
Operating Segments | Integrated | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		50	58	118	153
Operating Segments | Integrated | Other revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		5	5	18	17
Operating Segments | Integrated | Other revenue unrelated to contracts with customers
Disaggregation of Revenue [Line Items]
Total revenues		15	7	31	27
Operating Segments | Stand-Alone Transmission
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		470	434	1,367	1,262
Total revenues		475	439	1,381	1,275
Operating Segments | Stand-Alone Transmission | Other revenue unrelated to contracts with customers
Disaggregation of Revenue [Line Items]
Total revenues		5	5	14	13
Operating Segments | Residential | Distribution
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		1,222	1,174	3,460	3,312
Operating Segments | Residential | Integrated
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		802	692	1,954	1,621
Operating Segments | Commercial | Distribution
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		395	405	1,153	1,156
Operating Segments | Commercial | Integrated
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		335	281	863	777
Operating Segments | Industrial | Distribution
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		138	150	437	575
Operating Segments | Industrial | Integrated
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		151	140	436	408
Operating Segments | Other | Distribution
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		18	18	56	52
Operating Segments | Other | Integrated
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		8	9	22	23
Operating Segments | ATSI | Stand-Alone Transmission
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		262	245	766	712
Operating Segments | TrAIL | Stand-Alone Transmission
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		68	72	206	204
Operating Segments | MAIT | Stand-Alone Transmission
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		116	101	330	288
Operating Segments | KATCo | Stand-Alone Transmission
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		24	16	67	58
Operating Segments | Other | Stand-Alone Transmission
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		0	0	(2)	0
Corporate/Other and Reconciling Adjustments
Disaggregation of Revenue [Line Items]
Total revenues		(15)	(13)	(42)	(40)
Corporate/Other and Reconciling Adjustments | Wholesale
Disaggregation of Revenue [Line Items]
Total revenues from contracts with customers		2	1	6	6
Corporate/Other and Reconciling Adjustments | Eliminations and reconciling adjustments
Disaggregation of Revenue [Line Items]
Total revenues		$ (17)	$ (14)	$ (48)	$ (46)

[1] Includes excise and gross receipts tax collections of $116 million and $114 million during the three months ended September 30, 2024 and 2023, respectively, and $329 million and $315 million during the nine months ended September 30, 2024 and 2023, respectively.