SAN ONOFRE NUCLEAR GENERATING STATION - NUCLEAR DECOMMISSIONING TRUSTS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Cost	$ 705		$ 705		$ 735
Gross unrealized gains	175		175		282
Gross unrealized losses	(64)		(64)		(5)
Estimated fair value	816		816		1,012
Proceeds from sales	133	$ 187	530	$ 729
Gross realized gains	2	9	16	48
Gross realized losses	(3)	$ (1)	(14)	$ (4)
Total debt securities
Debt Securities, Available-for-sale [Line Items]
Cost	581		581		620
Gross unrealized gains	3		3		20
Gross unrealized losses	(51)		(51)		(3)
Estimated fair value	533		533		637
U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Cost	34		34		56
Gross unrealized gains	2		2		0
Gross unrealized losses	(2)		(2)		0
Estimated fair value	34		34		56
Municipal bonds
Debt Securities, Available-for-sale [Line Items]
Cost	294		294		309
Gross unrealized gains	0		0		13
Gross unrealized losses	(21)		(21)		(1)
Estimated fair value	273		273		321
Other securities
Debt Securities, Available-for-sale [Line Items]
Cost	253		253		255
Gross unrealized gains	1		1		7
Gross unrealized losses	(28)		(28)		(2)
Estimated fair value	226		226		260
Equity securities
Debt Securities, Available-for-sale [Line Items]
Cost	110		110		104
Gross unrealized gains	172		172		262
Gross unrealized losses	(13)		(13)		(2)
Estimated fair value	269		269		364
Short-term investments, primarily cash equivalents
Debt Securities, Available-for-sale [Line Items]
Cost	17		17		3
Gross unrealized gains	0		0		0
Gross unrealized losses	0		0		0
Estimated fair value	17		17		3
Receivables (payables), net
Debt Securities, Available-for-sale [Line Items]
Cost	(3)		(3)		8
Gross unrealized gains	0		0		0
Gross unrealized losses	0		0		0
Estimated fair value	$ (3)		$ (3)		$ 8