SAN ONOFRE NUCLEAR GENERATING STATION - NUCLEAR DECOMMISSIONING TRUSTS (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Cost	$ 715		$ 715		$ 735
Gross unrealized gains	190		190		282
Gross unrealized losses	(42)		(42)		(5)
Estimated fair value	863		863		1,012
Proceeds from sales	155	$ 254	397	$ 542
Gross realized gains	3	18	14	39
Gross realized losses	(7)	$ (1)	(11)	$ (3)
Total debt securities
Debt Securities, Available-for-sale [Line Items]
Cost	604		604		620
Gross unrealized gains	3		3		20
Gross unrealized losses	(34)		(34)		(3)
Estimated fair value	573		573		637
U.S. government corporations and agencies
Debt Securities, Available-for-sale [Line Items]
Cost	43		43		56
Gross unrealized gains	1		1		0
Gross unrealized losses	(1)		(1)		0
Estimated fair value	43		43		56
Municipal bonds
Debt Securities, Available-for-sale [Line Items]
Cost	305		305		309
Gross unrealized gains	1		1		13
Gross unrealized losses	(13)		(13)		(1)
Estimated fair value	293		293		321
Other securities
Debt Securities, Available-for-sale [Line Items]
Cost	256		256		255
Gross unrealized gains	1		1		7
Gross unrealized losses	(20)		(20)		(2)
Estimated fair value	237		237		260
Equity securities
Debt Securities, Available-for-sale [Line Items]
Cost	109		109		104
Gross unrealized gains	187		187		262
Gross unrealized losses	(8)		(8)		(2)
Estimated fair value	288		288		364
Short-term investments, primarily cash equivalents
Debt Securities, Available-for-sale [Line Items]
Cost	15		15		3
Gross unrealized gains	0		0		0
Gross unrealized losses	0		0		0
Estimated fair value	15		15		3
Receivables (payables), net
Debt Securities, Available-for-sale [Line Items]
Cost	(13)		(13)		8
Gross unrealized gains	0		0		0
Gross unrealized losses	0		0		0
Estimated fair value	$ (13)		$ (13)		$ 8