Consolidated Statements of Changes in Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Jan. 01, 2019
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	$ 15,496	$ 12,652	$ 12,652
Net income	213	308
Other comprehensive income	2	2
Common stock issued, net of issuance cost	88
Cumulative effect of accounting changes				$ 0
Common stock dividends declared	(232)	(200)
Dividends to noncontrolling interests	(30)	(30)
Stock-based compensation		(18)
Noncash stock-based compensation	7	5
Balance, at the end of the period	$ 15,544	$ 12,719	15,496
Dividends declared per common share (in dollars per share)	$ 0.6375	$ 0.6125
Minimum
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock dividends (in dollars per share)	0.255	0.255
Preference stock dividends (in dollars per share)	15.625	15.625
Maximum
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock dividends (in dollars per share)	0.299	0.299
Preference stock dividends (in dollars per share)	$ 35.936	$ 35.936
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	$ 4,990	$ 2,545	2,545
Common stock issued, net of issuance cost	88
Noncash stock-based compensation	7	5
Balance, at the end of the period	5,085	2,550	4,990
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	(69)	(50)	(50)
Other comprehensive income	2	2
Cumulative effect of accounting changes				(10)
Balance, at the end of the period	(67)	(58)	(69)
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	8,382	7,964	7,964
Net income	183	278
Cumulative effect of accounting changes				10
Common stock dividends declared	(232)	(200)
Stock-based compensation		(18)
Balance, at the end of the period	8,333	8,034	8,382
Subtotal
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	13,303	10,459	10,459
Net income	183	278
Other comprehensive income	2	2
Common stock issued, net of issuance cost	88
Cumulative effect of accounting changes				0
Common stock dividends declared	(232)	(200)
Stock-based compensation		(18)
Noncash stock-based compensation	7	5
Balance, at the end of the period	13,351	10,526	13,303
Noncontrolling Interests, Preferred and Preference Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	2,193	2,193	2,193
Net income	30	30
Dividends to noncontrolling interests	(30)	(30)
Balance, at the end of the period	2,193	2,193	2,193
Southern California Edison
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	17,827	13,785	13,785
Net income	249	323
Other comprehensive income	2	1
Cumulative effect of accounting change			269
Cumulative effect of accounting changes				0
Common stock dividends declared	(269)	(200)
Dividends declared on preferred and preference stock	(30)	(30)
Stock-based compensation	(5)	(12)
Noncash stock-based compensation	3	3
Balance, at the end of the period	$ 18,046	$ 13,870	17,827
Dividends declared per common share (in dollars per share)	$ 0.6125	$ 0.6125
Southern California Edison | Minimum
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock dividends (in dollars per share)	0.255	0.255
Preference stock dividends (in dollars per share)	15.625	15.625
Southern California Edison | Maximum
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock dividends (in dollars per share)	0.299	0.299
Preference stock dividends (in dollars per share)	$ 35.936	$ 35.936
Southern California Edison | Preferred and Preference Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	$ 2,245	$ 2,245	2,245
Balance, at the end of the period	2,245	2,245	2,245
Southern California Edison | Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	2,168	2,168	2,168
Balance, at the end of the period	2,168	2,168	2,168
Southern California Edison | Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	3,939	680	680
Cumulative effect of accounting change			269
Stock-based compensation	(5)
Noncash stock-based compensation	4	3
Balance, at the end of the period	4,207	683	3,939
Southern California Edison | Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	(39)	(23)	(23)
Other comprehensive income	2	1
Cumulative effect of accounting changes				(5)
Balance, at the end of the period	(37)	(27)	(39)
Southern California Edison | Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	9,514	8,715	8,715
Net income	249	323
Cumulative effect of accounting changes				$ 5
Common stock dividends declared	(269)	(200)
Dividends declared on preferred and preference stock	(30)	(30)
Stock-based compensation		(12)
Noncash stock-based compensation	(1)
Balance, at the end of the period	$ 9,463	$ 8,801	$ 9,514