SAN ONOFRE NUCLEAR GENERATING STATION - NUCLEAR DECOMMISSIONING TRUSTS (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Cost	$ 666		$ 661
Gross unrealized gains	243		233
Gross unrealized losses	(23)		(22)
Estimated fair value	886		872
Proceeds from sales	181	$ 156
Gross realized gains	14	2
Gross realized losses	(2)	$ (3)
Short-term investments, primarily cash equivalents
Debt Securities, Available-for-sale [Line Items]
Cost	28		21
Gross unrealized gains	0		0
Gross unrealized losses	0		0
Estimated fair value	28		21
Equity securities
Debt Securities, Available-for-sale [Line Items]
Cost	89		89
Gross unrealized gains	239		225
Gross unrealized losses	(3)		(2)
Estimated fair value	325		312
Total debt securities
Debt Securities, Available-for-sale [Line Items]
Cost	567		558
Gross unrealized gains	4		8
Gross unrealized losses	(20)		(20)
Estimated fair value	551		546
Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Cost	59		50
Gross unrealized gains	1		2
Gross unrealized losses	(1)		(1)
Estimated fair value	59		51
Municipal bonds
Debt Securities, Available-for-sale [Line Items]
Cost	277		280
Gross unrealized gains	2		3
Gross unrealized losses	(9)		(8)
Estimated fair value	270		275
Other securities
Debt Securities, Available-for-sale [Line Items]
Cost	231		228
Gross unrealized gains	1		3
Gross unrealized losses	(10)		(11)
Estimated fair value	222		220
Receivables (payables), net
Debt Securities, Available-for-sale [Line Items]
Cost	(18)		(7)
Gross unrealized gains	0		0
Gross unrealized losses	0		0
Estimated fair value	$ (18)		$ (7)