CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - USD ($) $ in Millions	Total		Common Stock [Member]	Retained earnings [Member]	Accumulated other comprehensive income (loss) [Member]	Shareholders' equity [Member]	Non-controlling interests [Member]	San Diego Gas and Electric Company [Member]		San Diego Gas and Electric Company [Member] Common Stock [Member]	San Diego Gas and Electric Company [Member] Retained earnings [Member]	San Diego Gas and Electric Company [Member] Accumulated other comprehensive income (loss) [Member]	San Diego Gas and Electric Company [Member] Shareholders' equity [Member]	San Diego Gas and Electric Company [Member] Non-controlling interests [Member]	Southern California Gas Company [Member]	Southern California Gas Company [Member] Preferred stock [Member]	Southern California Gas Company [Member] Common Stock [Member]	Southern California Gas Company [Member] Retained earnings [Member]	Southern California Gas Company [Member] Accumulated other comprehensive income (loss) [Member]
Beginning Balance at Dec. 31, 2014	$ 12,100		$ 2,484	$ 9,339	$ (497)	$ 11,326	$ 774	$ 4,992		$ 1,338	$ 3,606	$ (12)	$ 4,932	$ 60	$ 2,781	$ 22	$ 866	$ 1,911	$ (18)
Net income	1,448	[1]		1,350		1,350	98	606	[1]		587		587	19	420			420
Comprehensive income (loss)	(334)				(309)	(309)	(25)	10				4	4	6	(1)				(1)
Share-based compensation expense	52		52			52
Preferred stock dividends declared															(1)			(1)
Common stock dividends declared	(694)			(694)		(694)		(300)			(300)		(300)		(50)			(50)
Preferred dividends of subsidiary	(1)			(1)		(1)
Issuances of common stock	107		107			107
Repurchases of common stock	(74)		(74)			(74)
Tax benefit related to share-based compensation	52		52			52
Distributions to noncontrolling interests	(80)						(80)	(32)						(32)
Equity contributed by noncontrolling interests	3						3
Ending balance at Dec. 31, 2015	12,579		2,621	9,994	(806)	11,809	770	5,276		1,338	3,893	(8)	5,223	53	3,149	22	866	2,280	(19)
Cumulative-effect adjustment from change in accounting principle	107			107		107		23			23		23		15			15
Net income	1,519	[1]		1,371		1,371	148	565	[1]		570		570	(5)	350			350
Comprehensive income (loss)	52				38	38	14	10						10	(3)				(3)
Share-based compensation expense	52		52			52
Preferred stock dividends declared															(1)			(1)
Common stock dividends declared	(754)			(754)		(754)		(175)			(175)		(175)
Preferred dividends of subsidiary	(1)			(1)		(1)
Issuances of common stock	104		104			104
Repurchases of common stock	(56)		(56)			(56)
Sale of noncontrolling interests, net of offering costs	1,701		261		20	281	1,420
Distributions to noncontrolling interests	(65)						(65)	(23)						(23)
Equity contributed by noncontrolling interests	3						3	2						2
Ending balance at Dec. 31, 2016	15,241	[2]	2,982	10,717	(748)	12,951	2,290	5,678	[2]	1,338	4,311	(8)	5,641	37	3,510	22	866	2,644	(22)
Net income	351			257		257	94	421			407		407	14	397			397
Comprehensive income (loss)	142				122	122	20	11						11	1				1
Share-based compensation expense	82		82			82
Preferred stock dividends declared															(1)			(1)
Common stock dividends declared	(826)			(826)		(826)		(450)			(450)		(450)
Preferred dividends of subsidiary	(1)			(1)		(1)
Issuances of common stock	100		100			100
Repurchases of common stock	(15)		(15)			(15)
Sale of noncontrolling interests, net of offering costs	196						196
Distributions to noncontrolling interests	(132)						(132)	(35)						(35)
Equity contributed by noncontrolling interests	2						2	1						1
Ending balance at Dec. 31, 2017	$ 15,140		$ 3,149	$ 10,147	$ (626)	$ 12,670	$ 2,470	$ 5,626		$ 1,338	$ 4,268	$ (8)	$ 5,598	$ 28	$ 3,907	$ 22	$ 866	$ 3,040	$ (21)

[1] As adjusted for the retrospective adoption of ASU 2016-15 and ASU 2016-18, which we discuss in Note 2.

[2] Reflects reclassifications to conform to current year presentation, which we discuss in Note 1.