SAN ONOFRE NUCLEAR GENERATING STATION - NUCLEAR DECOMMISSIONING TRUSTS (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Cost	$ 668		$ 668		$ 689
Gross unrealized gains	203		203		196
Gross unrealized losses	(44)		(44)		(44)
Estimated fair value	827		827		841
Proceeds from sales	143	$ 133	437	$ 530
Gross realized gains	12	2	20	16
Gross realized losses	(3)	$ (3)	(9)	$ (14)
Total debt securities
Debt Securities, Available-for-sale [Line Items]
Cost	556		556		571
Gross unrealized gains	2		2		2
Gross unrealized losses	(39)		(39)		(36)
Estimated fair value	519		519		537
U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Cost	44		44		40
Gross unrealized gains	1		1		1
Gross unrealized losses	(2)		(2)		(1)
Estimated fair value	43		43		40
Municipal bonds
Debt Securities, Available-for-sale [Line Items]
Cost	278		278		283
Gross unrealized gains	0		0		1
Gross unrealized losses	(18)		(18)		(14)
Estimated fair value	260		260		270
Other securities
Debt Securities, Available-for-sale [Line Items]
Cost	234		234		248
Gross unrealized gains	1		1		0
Gross unrealized losses	(19)		(19)		(21)
Estimated fair value	216		216		227
Equity securities
Debt Securities, Available-for-sale [Line Items]
Cost	99		99		111
Gross unrealized gains	201		201		194
Gross unrealized losses	(5)		(5)		(8)
Estimated fair value	295		295		297
Short-term investments, primarily cash equivalents
Debt Securities, Available-for-sale [Line Items]
Cost	24		24		11
Gross unrealized gains	0		0		0
Gross unrealized losses	0		0		0
Estimated fair value	24		24		11
Receivables (payables), net
Debt Securities, Available-for-sale [Line Items]
Cost	(11)		(11)		(4)
Gross unrealized gains	0		0		0
Gross unrealized losses	0		0		0
Estimated fair value	$ (11)		$ (11)		$ (4)