SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Revenues Disaggregated by Type of Customer) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Disaggregation of Revenue [Abstract]
Total operating revenues	$ 5,983	$ 5,861
Electric
Disaggregation of Revenue [Abstract]
Total operating revenues	4,135	4,052
Natural gas
Disaggregation of Revenue [Abstract]
Total operating revenues	1,848	1,809
Utility
Disaggregation of Revenue [Abstract]
Total operating revenues	5,983	5,861
Utility | Electric
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	4,069	4,043
Regulatory balancing accounts	66	9
Total operating revenues	4,135	4,052
Utility | Electric | Residential
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	1,834	1,799
Utility | Electric | Commercial
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	1,506	1,505
Utility | Electric | Industrial
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	414	413
Utility | Electric | Agricultural
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	199	180
Utility | Electric | Public street and highway lighting
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	27	25
Utility | Electric | Other, net
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	89	121
Utility | Natural gas
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	2,534	2,301
Regulatory balancing accounts	(686)	(492)
Total operating revenues	1,848	1,809
Utility | Natural gas | Residential
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	1,709	1,517
Utility | Natural gas | Commercial
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	399	373
Utility | Natural gas | Other, net
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	(120)	(64)
Utility | Natural gas | Transportation service only
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	$ 546	$ 475