CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Preferred Stock [Member]	Preferred Stock [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock [Member]	Common Stock [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Retained earnings [Member]	Retained earnings [Member] Cumulative Effect, Period of Adoption, Adjustment	Retained earnings [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated other comprehensive income (loss) [Member]	Accumulated other comprehensive income (loss) [Member] Cumulative Effect, Period of Adoption, Adjustment	Accumulated other comprehensive income (loss) [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Shareholders' equity [Member]	Shareholders' equity [Member] Cumulative Effect, Period of Adoption, Adjustment	Shareholders' equity [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Non-controlling interests [Member]	Non-controlling interests [Member] Cumulative Effect, Period of Adoption, Adjustment	Non-controlling interests [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	San Diego Gas and Electric Company [Member]	San Diego Gas and Electric Company [Member] Cumulative Effect, Period of Adoption, Adjustment	San Diego Gas and Electric Company [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	San Diego Gas and Electric Company [Member] Common Stock [Member]	San Diego Gas and Electric Company [Member] Common Stock [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	San Diego Gas and Electric Company [Member] Retained earnings [Member]	San Diego Gas and Electric Company [Member] Retained earnings [Member] Cumulative Effect, Period of Adoption, Adjustment	San Diego Gas and Electric Company [Member] Retained earnings [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	San Diego Gas and Electric Company [Member] Accumulated other comprehensive income (loss) [Member]	San Diego Gas and Electric Company [Member] Accumulated other comprehensive income (loss) [Member] Cumulative Effect, Period of Adoption, Adjustment	San Diego Gas and Electric Company [Member] Accumulated other comprehensive income (loss) [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	San Diego Gas and Electric Company [Member] Shareholders' equity [Member]	San Diego Gas and Electric Company [Member] Shareholders' equity [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	San Diego Gas and Electric Company [Member] Non-controlling interests [Member]	San Diego Gas and Electric Company [Member] Non-controlling interests [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Southern California Gas Company [Member]	Southern California Gas Company [Member] Cumulative Effect, Period of Adoption, Adjustment	Southern California Gas Company [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Southern California Gas Company [Member] Preferred Stock [Member]	Southern California Gas Company [Member] Preferred Stock [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Southern California Gas Company [Member] Common Stock [Member]	Southern California Gas Company [Member] Common Stock [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Southern California Gas Company [Member] Retained earnings [Member]	Southern California Gas Company [Member] Retained earnings [Member] Cumulative Effect, Period of Adoption, Adjustment	Southern California Gas Company [Member] Retained earnings [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Southern California Gas Company [Member] Accumulated other comprehensive income (loss) [Member]	Southern California Gas Company [Member] Accumulated other comprehensive income (loss) [Member] Cumulative Effect, Period of Adoption, Adjustment	Southern California Gas Company [Member] Accumulated other comprehensive income (loss) [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Preferred Class A [Member]	Preferred Class A [Member] Preferred Stock [Member]	Preferred Class A [Member] Retained earnings [Member]	Preferred Class A [Member] Shareholders' equity [Member]	Preferred Class B [Member]	Preferred Class B [Member] Preferred Stock [Member]	Preferred Class B [Member] Retained earnings [Member]	Preferred Class B [Member] Shareholders' equity [Member]	Series C Preferred Stock [Member]	Series C Preferred Stock [Member] Preferred Stock [Member]	Series C Preferred Stock [Member] Retained earnings [Member]	Series C Preferred Stock [Member] Shareholders' equity [Member]
Beginning Balance at Dec. 31, 2017	$ 15,140	$ (1)	$ 15,139	$ 0	$ 0	$ 3,149	$ 3,149	$ 10,147	$ 2	$ 10,149	$ (626)	$ (3)	$ (629)	$ 12,670	$ (1)	$ 12,669	$ 2,470		$ 2,470	$ 5,626			$ 1,338		$ 4,268			$ (8)			$ 5,598		$ 28		$ 3,907			$ 22		$ 866		$ 3,040			$ (21)
Accounting Standards Update [Extensible List]																				us-gaap:AccountingStandardsUpdate201802Member															us-gaap:AccountingStandardsUpdate201802Member
Net income	1,126							1,050						1,050			76			$ 676					669						669		7		$ 401							401
Other comprehensive income (loss)	(133)										(135)			(135)			2			6								(2)			(2)		8		1										1
Share-based compensation expense	83					83								83
Preferred stock dividends declared																																			(1)							(1)						$ (105)		$ (105)	$ (105)	$ (20)		$ (20)	$ (20)
Common stock dividends declared	(969)							(969)						(969)						(250)					(250)						(250)				(50)							(50)
Preferred dividends of subsidiary	(1)							(1)						(1)
Issuances of stock	2,326					2,326								2,326																																		1,693	$ 1,693		1,693	565	$ 565		565
Repurchases of common stock	(21)					(21)								(21)
Contributions	66																66			65													65
Distributions	(110)																(110)			(8)													(8)
Purchases	(8)					(1)								(1)			(7)
Sales, net of offering costs	90					4								4			86
Acquisition	13																13
Deconsolidations	(486)																(486)
Ending balance at Dec. 31, 2018	19,248		19,263	2,258	2,258	5,540	5,540	10,104		10,161	(764)		(806)	17,138		17,153	2,110		2,110	6,115	$ 0	$ 6,115	1,338	$ 1,338	4,687	$ 2	$ 4,689	(10)	$ (2)	$ (12)	6,015	$ 6,015	100	$ 100	4,258	$ (2)	$ 4,256	22	$ 22	866	$ 866	3,390	$ 2	$ 3,392	(20)	$ (4)	$ (24)
Ending balance (Accounting Standards Update 2016-02 [Member]) at Dec. 31, 2018		17							17						17
Ending balance (Accounting Standards Update 2018-02 [Member]) at Dec. 31, 2018		(2)							40			$ (42)			(2)
Net income	2,362							2,198						2,198			164			774					767						767		7		642							642
Other comprehensive income (loss)	(140)										(133)			(133)			(7)			(2)								(4)			(4)		2		1										1
Share-based compensation expense	75					75								75
Preferred stock dividends declared																																			(1)							(1)						(103)		(103)	(103)	(39)		(39)	(39)
Common stock dividends declared	(1,086)							(1,086)						(1,086)																					(150)							(150)
Equity contribution from Sempra Energy																				322			322								322
Preferred dividends of subsidiary	(1)							(1)						(1)
Issuances of stock	1,885					1,885								1,885
Repurchases of common stock	(26)					(26)								(26)
Contributions	175																175			175													175
Distributions	(98)					5								5			(103)			(3)													(3)
Purchases	(30)					(3)								(3)			(27)
Sales, net of offering costs	5					4								4			1
Acquisition	3																3
Deconsolidations	(440)																(440)			(281)													(281)
Ending balance at Dec. 31, 2019	21,805	$ (9)	$ 21,796	2,258	$ 2,258	7,480	$ 7,480	11,130	$ (7)	$ 11,123	(939)		$ (939)	19,929	$ (7)	$ 19,922	1,876	$ (2)	$ 1,874	7,100			1,660		5,456			(16)			7,100		0		4,748			22		866		3,883			(23)
Net income	4,105							3,933						3,933			172			824					824						824		0		505							505
Other comprehensive income (loss)	422										446			446			(24)			6								6			6		0		(8)										(8)
Share-based compensation expense	71					71								71
Preferred stock dividends declared																																			(1)							(1)						$ (104)		$ (104)	$ (104)	$ (39)		$ (39)	$ (39)	$ (25)		$ (25)	$ (25)
Common stock dividends declared	(1,214)							(1,214)						(1,214)						(200)					(200)						(200)				(100)							(100)
Preferred dividends of subsidiary	(1)							(1)						(1)
Issuances of stock	33					33								33																																										$ 889	$ 889		$ 889
Repurchases of common stock	(566)					(566)								(566)
Contributions	1																1
Distributions	(1)																(1)
Purchases	(248)					34					(7)			27			(275)
Sales, net of offering costs	28					1								1			27
Acquisition	1																1
Equitization of long-term debt for deficit held by NCI	22																22
Deconsolidations	(236)																(236)
Ending balance at Dec. 31, 2020	$ 24,934			$ 3,147		$ 7,053		$ 13,673			$ (500)			$ 23,373			$ 1,561			$ 7,730			$ 1,660		$ 6,080			$ (10)			$ 7,730		$ 0		$ 5,144			$ 22		$ 866		$ 4,287			$ (31)