Consolidated Statements of Changes in Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Jan. 01, 2019	Jan. 01, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	$ 12,652	$ 13,866
Net income	308	245
Net income	308	242
Other comprehensive income	2	2
Cumulative effect of accounting changes			$ 0	$ 5
Common stock dividends declared	(200)	(197)
Dividends to noncontrolling interests	(30)	(30)
Stock-based compensation	(18)	(8)
Noncash stock-based compensation	5	5
Other		1
Balance, at the end of the period	$ 12,719	$ 13,889
Dividends declared per common share (in dollars per share)	$ 0.6125	$ 0.6050
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	$ 2,545	$ 2,526
Noncash stock-based compensation	5	5
Balance, at the end of the period	2,550	2,531
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	(50)	(43)
Other comprehensive income	2	2
Cumulative effect of accounting changes			(10)	(5)
Balance, at the end of the period	(58)	(46)
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	7,964	9,188
Net income	278	218
Cumulative effect of accounting changes			10	10
Common stock dividends declared	(200)	(197)
Stock-based compensation	(18)	(8)
Balance, at the end of the period	8,034	9,211
Subtotal
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	10,459	11,671
Net income	278	218
Other comprehensive income	2	2
Cumulative effect of accounting changes				5
Common stock dividends declared	(200)	(197)
Stock-based compensation	(18)	(8)
Noncash stock-based compensation	5	5
Balance, at the end of the period	10,526	11,696
Noncontrolling Interests, Other
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period		2
Net income		(3)
Other		1
Balance, at the end of the period		0
Preferred and Preference Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	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
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
Southern California Edison
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	$ 13,785	$ 14,672
Net income	323	316
Other comprehensive income	1	2
Cumulative effect of accounting changes			0	0
Common stock dividends declared	(200)	(212)
Dividends declared on preferred and preference stock	(30)	(30)
Stock-based compensation	(12)	(2)
Noncash stock-based compensation	3	2
Balance, at the end of the period	$ 13,870	$ 14,748
Dividends declared per common share (in dollars per share)	$ 0.4599	$ 0.4875
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
Balance, at the end of the period	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
Balance, at the end of the period	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	680	671
Noncash stock-based compensation	3	2
Balance, at the end of the period	683	673
Southern California Edison | Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	(23)	(19)
Other comprehensive income	1	2
Cumulative effect of accounting changes			(5)	(5)
Balance, at the end of the period	(27)	(22)
Southern California Edison | Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	8,715	9,607
Net income	323	316
Cumulative effect of accounting changes			$ 5	$ 5
Common stock dividends declared	(200)	(212)
Dividends declared on preferred and preference stock	(30)	(30)
Stock-based compensation	(12)	(2)
Balance, at the end of the period	$ 8,801	$ 9,684
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