Consolidated Statements of Changes in Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period			$ 14,187	$ 13,388
Net income			702	622
Net income	$ 309	$ 308	701	614
Other comprehensive income (loss)	1	1	5	3
Dividends declared on common stock			(354)	(313)
Dividends to noncontrolling interests			(62)	(61)
Stock-based compensation			(151)	(18)
Non-cash stock-based compensation			10	12
Issuance of preference stock			463	294
Redemption of preference stock				(125)
Balance, at the end of the period	$ 14,800	$ 13,802	$ 14,800	$ 13,802
Dividends declared per common share (in dollars per share)	$ 0.5425	$ 0.4800	$ 1.0850	$ 0.96
Accounting for Share-Based Payments
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		$ 546
Stock-based compensation		(60)
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period			$ 2,505	$ 2,484
Non-cash stock-based compensation			10	12
Balance, at the end of the period	$ 2,515	2,496	2,515	2,496
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period			(53)	(56)
Other comprehensive income (loss)			5	3
Balance, at the end of the period	(48)	(53)	(48)	(53)
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period			9,544	8,940
Net income			640	561
Dividends declared on common stock			(354)	(313)
Stock-based compensation			(151)	(18)
Redemption of preference stock				(2)
Balance, at the end of the period	9,679	9,168	9,679	9,168
Subtotal
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period			11,996	11,368
Net income			640	561
Other comprehensive income (loss)			5	3
Dividends declared on common stock			(354)	(313)
Stock-based compensation			(151)	(18)
Non-cash stock-based compensation			10	12
Redemption of preference stock				(2)
Balance, at the end of the period	12,146	11,611	12,146	11,611
Preferred and Preference Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period			2,191	2,020
Net income			62	61
Dividends to noncontrolling interests			(62)	(61)
Issuance of preference stock			463	294
Redemption of preference stock				(123)
Balance, at the end of the period	2,654	2,191	2,654	2,191
Southern California Edison
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period			14,483	13,672
Net income	338	349	718	673
Other comprehensive income (loss)	0	1	2	2
Dividends declared on common stock			(382)	(340)
Dividends declared on preferred and preference stock			(62)	(61)
Stock-based compensation			(33)	(34)
Non-cash stock-based compensation			6	6
Issuance of preference stock			463	294
Redemption of preference stock				(125)
Balance, at the end of the period	15,195	14,087	15,195	14,087
Southern California Edison | Accounting for Share-Based Payments
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		662
Stock-based compensation		(40)
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	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			657	652
Non-cash stock-based compensation			6	6
Issuance of preference stock			(12)	(6)
Redemption of preference stock				2
Balance, at the end of the period	651	654	651	654
Southern California Edison | Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period			(20)	(22)
Other comprehensive income (loss)			2	2
Balance, at the end of the period	(18)	(20)	(18)	(20)
Southern California Edison | Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period			9,433	8,804
Net income			718	673
Dividends declared on common stock			(382)	(340)
Dividends declared on preferred and preference stock			(62)	(61)
Stock-based compensation			(33)	(34)
Redemption of preference stock				(2)
Balance, at the end of the period	9,674	9,040	9,674	9,040
Southern California Edison | Preferred and Preference Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period			2,245	2,070
Issuance of preference stock			475	300
Redemption of preference stock				(125)
Balance, at the end of the period	$ 2,720	$ 2,245	$ 2,720	$ 2,245