GENERAL INFORMATION AND OTHER FINANCIAL DATA - EARNINGS PER SHARE (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Income from continuing operations, net of income tax	$ 455	$ 528	$ 1,383	$ 1,395
Earnings attributable to noncontrolling interests	(10)	(26)	(43)	(169)
Preferred dividends	(20)	(37)	(41)	(73)
Preferred dividends of subsidiary	(1)	(1)	(1)	(1)
Earnings from continuing operations attributable to common shares for basic EPS	424	464	1,298	1,152
Add back dividends for dilutive mandatory convertible preferred stock	0	0	0	52
Earnings from continuing operations attributable to common shares for diluted EPS	424	464	1,298	1,204
Income from discontinued operations, net of income tax	0	1,777	0	1,857
Earnings attributable to noncontrolling interests	0	(2)	0	(10)
Earnings from discontinued operations attributable to Sempra	0	1,775	0	1,847
Earnings attributable to common shares for basic EPS	424	2,239	1,298	2,999
Earnings attributable to common shares	$ 424	$ 2,239	$ 1,298	$ 3,051
Weighted-average common shares outstanding for basic EPS	307,800,000	293,060,000	304,372,000	292,925,000
Dilutive effect of stock options, RSAs and RSUs (in shares)	807,000	1,095,000	846,000	1,199,000
Dilutive effect of mandatory convertible preferred stock (in shares)	0	0	1,066,000	13,838,000
Weighted-average common shares outstanding for diluted EPS (in shares)	308,607,000	294,155,000	306,284,000	307,962,000
Earnings from continuing operations (in dollars per share)	$ 1.38	$ 1.58	$ 4.27	$ 3.93
Earnings from discontinued operations (in dollars per share)	0	6.06	0	6.31
Earnings attributable to common shares (in dollars per share)	1.38	7.64	4.27	10.24
Earnings from continuing operations (in dollars per share)	1.37	1.58	4.24	3.91
Earnings from discontinued operations (in dollars per share)	0	6.03	0	6.00
Earnings from continuing operations attributable to common shares (in dollars per share)	$ 1.37	$ 7.61	$ 4.24	$ 9.91
Vested RSUs included in basic WASO (in shares)	447,000	530,000	454,000	536,000
Performance-based RSUs [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Equity awards, granted (in shares)			323,889
Service-based RSUs [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Equity awards, granted (in shares)			142,105
Stock options, RSAs and RSUs [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Non-qualified stock options granted (in shares)			222,620
Stock options, RSAs and RSUs [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Antidilutive securities excluded from earnings per share (in shares)	145,247	216,922	287,061	235,589
Convertible Preferred Stock [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Antidilutive securities excluded from earnings per share (in shares)	4,256,725	18,450,579	4,256,725	4,612,645