SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Summary of Revenues Disaggregated by Type of Customer) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Disaggregation of Revenue [Abstract]
Total operating revenues	$ 6,881	$ 5,983
Electric
Disaggregation of Revenue [Abstract]
Total operating revenues	4,967	4,135
Natural gas
Disaggregation of Revenue [Abstract]
Total operating revenues	1,914	1,848
Utility
Disaggregation of Revenue [Abstract]
Total operating revenues	6,881	5,983
Utility | Electric
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	4,361	4,069
Regulatory balancing accounts	606	66
Total operating revenues	4,967	4,135
Utility | Electric | Residential
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	1,807	1,834
Utility | Electric | Commercial
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	1,592	1,506
Utility | Electric | Industrial
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	438	414
Utility | Electric | Agricultural
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	205	199
Utility | Electric | Public street and highway lighting
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	26	27
Utility | Electric | Other, net
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	293	89
Utility | Natural gas
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	2,016	2,534
Regulatory balancing accounts	(102)	(686)
Total operating revenues	1,914	1,848
Utility | Natural gas | Residential
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	1,480	1,709
Utility | Natural gas | Commercial
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	368	399
Utility | Natural gas | Transportation service only
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	490	546
Utility | Natural gas | Other, net
Disaggregation of Revenue [Abstract]
Total revenue from contracts with customers	$ (322)	$ (120)