Consolidated Statements of Changes in Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended						9 Months Ended		12 Months Ended
	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	$ 16,446	$ 15,544	$ 15,496	$ 12,913	$ 12,719	$ 12,652	$ 15,496	$ 12,652
Net income (loss)	(242)	348	213	502	422	308
Other comprehensive income	2	2	2	2	1	2
Common stock issued, net of issuance cost	15	815	88	2,185
Common stock dividends declared	(241)	(241)	(232)	(219)	(200)	(200)
Dividends to noncontrolling interests	(31)	(30)	(30)	(31)	(30)	(30)
Stock-based compensation				(5)	(4)	(18)
Noncash stock-based compensation	8	8	7	6	5	5
Redemption of preferred and preference stock	308
Balance, at the end of the period	$ 15,649	$ 16,446	$ 15,544	$ 15,353	$ 12,913	$ 12,719	15,649	15,353	$ 12,652
Dividends declared per common share (in dollars per share)	$ 0.6375	$ 0.6375	$ 0.6375	$ 0.6125	$ 0.6125	$ 0.6125
Accounting Standards Update [Extensible List]									us-gaap:AccountingStandardsUpdate201802Member
Cumulative effect adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period						$ 0		0
Balance, at the end of the period									$ 0
Minimum
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock, dividends per share, declared (in dollars per share)	0.247	0.255	0.255	0.255	0.255	$ 0.255
Preference stock, dividends per share, declared (in dollars per share)	15.625	15.625	15.625	15.625	15.625	15.625
Maximum
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock, dividends per share, declared (in dollars per share)	0.289	0.299	0.299	0.299	0.299	0.299
Preference stock, dividends per share, declared (in dollars per share)	$ 35.936	$ 35.936	$ 35.936	$ 35.936	$ 35.936	$ 35.936
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	$ 5,908	$ 5,085	$ 4,990	$ 2,555	$ 2,550	$ 2,545	4,990	2,545
Common stock issued, net of issuance cost	15	815	88	2,185
Noncash stock-based compensation	7	8	7	6	5	5
Balance, at the end of the period	5,930	5,908	5,085	4,746	2,555	2,550	5,930	4,746	2,545
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	(65)	(67)	(69)	(57)	(58)	(50)	(69)	(50)
Other comprehensive income	2	2	2	2	1	2
Balance, at the end of the period	(63)	(65)	(67)	(55)	(57)	(58)	(63)	(55)	(50)
Accumulated Other Comprehensive Loss | Cumulative effect adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period						(10)		(10)
Balance, at the end of the period									(10)
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	8,410	8,333	8,382	8,222	8,034	7,964	8,382	7,964
Net income (loss)	(288)	318	183	471	392	278
Common stock dividends declared	(241)	(241)	(232)	(219)	(200)	(200)
Stock-based compensation				(5)	(4)	(18)
Balance, at the end of the period	7,881	8,410	8,333	8,469	8,222	8,034	7,881	8,469	7,964
Retained Earnings | Cumulative effect adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period						10		10
Balance, at the end of the period									10
Subtotal
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	14,253	13,351	13,303	10,720	10,526	10,459	13,303	10,459
Net income (loss)	(288)	318	183	471	392	278
Other comprehensive income	2	2	2	2	1	2
Common stock issued, net of issuance cost	15	815	88	2,185
Common stock dividends declared	(241)	(241)	(232)	(219)	(200)	(200)
Stock-based compensation				(5)	(4)	(18)
Noncash stock-based compensation	7	8	7	6	5	5
Balance, at the end of the period	13,748	14,253	13,351	13,160	10,720	10,526	13,748	13,160	10,459
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	2,193	2,193	2,193	2,193	2,193
Net income (loss)	46	30	30	31	30	30
Dividends to noncontrolling interests	(31)	(30)	(30)	(31)	(30)	(30)
Noncash stock-based compensation	1
Redemption of preferred and preference stock	(308)
Balance, at the end of the period	1,901	2,193	2,193	2,193	2,193	2,193	1,901	2,193	2,193
Southern California Edison
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	18,781	18,046	17,827	15,492	13,870	13,785	17,827	13,785
Net income (loss)	(218)	411	249	534	449	323
Other comprehensive income	1	1	2	1	1	1
Capital contribution from Edison International Parent	219	619	269	1,850	1,200
Common stock dividends declared	(269)	(269)	(269)	(200)		(200)
Dividends declared on preferred and preference stock	(31)	(30)	(30)	(31)	(30)	(30)
Stock-based compensation			(5)	(4)	(1)	(12)
Noncash stock-based compensation	4	3	3	3	3	3
Redemption of preferred and preference stock	(120)						(308)
Balance, at the end of the period	$ 18,179	$ 18,781	$ 18,046	$ 17,645	$ 15,492	$ 13,870	18,179	17,645	$ 13,785
Dividends declared per common share (in dollars per share)	$ 0.6185	$ 0.6185	$ 0.6185	$ 0.4599		$ 0.4599
Accounting Standards Update [Extensible List]									us-gaap:AccountingStandardsUpdate201802Member
Southern California Edison | Cumulative effect adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period						$ 0		0
Balance, at the end of the period									$ 0
Southern California Edison | Minimum
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock, dividends per share, declared (in dollars per share)	0.247	0.255	0.255	$ 0.255	$ 0.255	$ 0.255
Preference stock, dividends per share, declared (in dollars per share)	15.625	15.625	15.625		15.625	15.625
Southern California Edison | Maximum
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Preferred stock, dividends per share, declared (in dollars per share)	0.289	0.299	0.299		0.299	0.299
Preference stock, dividends per share, declared (in dollars per share)	$ 35.936	$ 35.936	$ 35.936		$ 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	$ 2,245	$ 2,245	$ 2,245	2,245	2,245
Redemption of preferred and preference stock	(300)
Balance, at the end of the period	1,945	2,245	2,245	2,245	2,245	2,245	1,945	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	2,168	2,168	2,168	2,168	2,168
Balance, at the end of the period	2,168	2,168	2,168	2,168	2,168	2,168	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	4,829	4,207	3,939	1,886	683	680	3,939	680
Capital contribution from Edison International Parent	219	619	269	1,850	1,200
Stock-based compensation			(5)	(2)
Noncash stock-based compensation	3	3	4	3	3	3
Redemption of preferred and preference stock	7
Balance, at the end of the period	5,058	4,829	4,207	3,737	1,886	683	5,058	3,737	680
Southern California Edison | Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	(36)	(37)	(39)	(26)	(27)	(23)	(39)	(23)
Other comprehensive income	1	1	2	1	1	1
Balance, at the end of the period	(35)	(36)	(37)	(25)	(26)	(27)	(35)	(25)	(23)
Southern California Edison | Accumulated Other Comprehensive Loss | Cumulative effect adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period						(5)		(5)
Balance, at the end of the period									(5)
Southern California Edison | Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	9,575	9,463	9,514	9,219	8,801	8,715	9,514	8,715
Net income (loss)	(218)	411	249	534	449	323
Common stock dividends declared	(269)	(269)	(269)	(200)		(200)
Dividends declared on preferred and preference stock	(31)	(30)	(30)	(31)	(30)	(30)
Stock-based compensation				(2)	(1)	(12)
Noncash stock-based compensation	1		(1)
Redemption of preferred and preference stock	(15)
Balance, at the end of the period	$ 9,043	$ 9,575	$ 9,463	$ 9,520	$ 9,219	8,801	$ 9,043	9,520	8,715
Southern California Edison | Retained Earnings | Cumulative effect adjustment
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period						$ 5		$ 5
Balance, at the end of the period									$ 5