Consolidated Statements of Changes in Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	$ 14,187	$ 13,388
Net income	393	311
Net income	392	306
Other comprehensive income (loss)	4	2
Dividends declared on common stock	(177)	(156)
Dividends to noncontrolling interests	(31)	(30)
Stock-based compensation	(139)	(8)
Non-cash stock-based compensation	5	6
Issuance of preference stock		294
Redemption of preference stock		(125)
Balance, at the end of the period	$ 14,242	$ 13,682
Dividends declared per common share (in dollars per share)	$ 0.5425	$ 0.4800
Accounting for Share-Based Payments
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		$ 271
Stock-based compensation		(50)
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	5	6
Balance, at the end of the period	2,510	2,490
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	(53)	(56)
Other comprehensive income (loss)	4	2
Balance, at the end of the period	(49)	(54)
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	9,544	8,940
Net income	362	281
Dividends declared on common stock	(177)	(156)
Stock-based compensation	(139)	(8)
Redemption of preference stock		(3)
Balance, at the end of the period	9,590	9,054
Subtotal
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	11,996	11,368
Net income	362	281
Other comprehensive income (loss)	4	2
Dividends declared on common stock	(177)	(156)
Stock-based compensation	(139)	(8)
Non-cash stock-based compensation	5	6
Redemption of preference stock		(3)
Balance, at the end of the period	12,051	11,490
Preferred and Preference Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	2,191	2,020
Net income	31	30
Dividends to noncontrolling interests	(31)	(30)
Issuance of preference stock		294
Redemption of preference stock		(122)
Balance, at the end of the period	2,191	2,192
Southern California Edison
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	14,483	13,672
Net income	380	325
Other comprehensive income (loss)	2	1
Dividends declared on common stock	(191)	(170)
Dividends declared on preferred and preference stock	(31)	(30)
Stock-based compensation	(23)	(28)
Non-cash stock-based compensation	3	3
Issuance of preference stock		294
Redemption of preference stock		(125)
Balance, at the end of the period	14,623	13,942
Southern California Edison | Accounting for Share-Based Payments
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income		317
Stock-based compensation		(34)
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	657	652
Non-cash stock-based compensation	3	3
Issuance of preference stock		(6)
Redemption of preference stock		3
Balance, at the end of the period	660	652
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	1
Balance, at the end of the period	(18)	(21)
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	380	325
Dividends declared on common stock	(191)	(170)
Dividends declared on preferred and preference stock	(31)	(30)
Stock-based compensation	(23)	(28)
Redemption of preference stock		(3)
Balance, at the end of the period	9,568	8,898
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		300
Redemption of preference stock		(125)
Balance, at the end of the period	$ 2,245	$ 2,245