Consolidated Statements of Changes in Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	$ 13,388	$ 12,982
Net income	301	327
Other comprehensive income	2	(1)
Common stock dividends declared	(156)	(136)
Dividends to noncontrolling interests	(30)	(28)
Stock-based compensation	(49)	(52)
Non-cash stock-based compensation	6	6
Issuance of preference stock	294
Redemption of preference stock	(125)
Balance, at the end of the period	$ 13,631	$ 13,098
Dividends declared per common share (in dollars per share)	$ 0.4800	$ 0.4175
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	$ 2,484	$ 2,445
Net income	0	0
Other comprehensive income	0	0
Common stock dividends declared	0	0
Dividends to noncontrolling interests	0	0
Stock-based compensation	1	9
Non-cash stock-based compensation	6	6
Issuance of preference stock	0
Redemption of preference stock	0
Balance, at the end of the period	2,491	2,460
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	(56)	(58)
Net income	0	0
Other comprehensive income	2	(1)
Common stock dividends declared	0	0
Dividends to noncontrolling interests	0	0
Stock-based compensation	0	0
Non-cash stock-based compensation	0	0
Issuance of preference stock	0
Redemption of preference stock	0
Balance, at the end of the period	(54)	(59)
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	8,940	8,573
Net income	271	299
Other comprehensive income	0	0
Common stock dividends declared	(156)	(136)
Dividends to noncontrolling interests	0	0
Stock-based compensation	(50)	(61)
Non-cash stock-based compensation	0	0
Issuance of preference stock	0
Redemption of preference stock	(3)
Balance, at the end of the period	9,002	8,675
Subtotal
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	11,368	10,960
Net income	271	299
Other comprehensive income	2	(1)
Common stock dividends declared	(156)	(136)
Dividends to noncontrolling interests	0	0
Stock-based compensation	(49)	(52)
Non-cash stock-based compensation	6	6
Issuance of preference stock	0
Redemption of preference stock	(3)
Balance, at the end of the period	11,439	11,076
Preferred and preference stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	2,020	2,022
Net income	30	28
Other comprehensive income	0	0
Common stock dividends declared	0	0
Dividends to noncontrolling interests	(30)	(28)
Stock-based compensation	0	0
Non-cash stock-based compensation	0	0
Issuance of preference stock	294
Redemption of preference stock	(122)
Balance, at the end of the period	2,192	2,022
Southern California Edison
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	13,672	13,282
Net income	317	333
Other comprehensive income	1	1
Common stock dividends declared	(170)	(147)
Dividends declared on preferred and preference stock	(30)	(28)
Stock-based compensation	(33)	(13)
Non-cash stock-based compensation	3	4
Issuance of preference stock	294
Redemption of preference stock	(125)
Balance, at the end of the period	13,929	13,432
Southern California Edison | Common stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	2,168	2,168
Net income	0	0
Other comprehensive income	0	0
Common stock dividends declared	0	0
Dividends declared on preferred and preference stock	0	0
Stock-based compensation	0	0
Non-cash stock-based compensation	0	0
Issuance of preference stock	0
Redemption of preference stock	0
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	652	618
Net income	0	0
Other comprehensive income	0	0
Common stock dividends declared	0	0
Dividends declared on preferred and preference stock	0	0
Stock-based compensation	1	9
Non-cash stock-based compensation	3	4
Issuance of preference stock	(6)
Redemption of preference stock	3
Balance, at the end of the period	653	631
Southern California Edison | Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	(22)	(28)
Net income	0	0
Other comprehensive income	1	1
Common stock dividends declared	0	0
Dividends declared on preferred and preference stock	0	0
Stock-based compensation	0	0
Non-cash stock-based compensation	0	0
Issuance of preference stock	0
Redemption of preference stock	0
Balance, at the end of the period	(21)	(27)
Southern California Edison | Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	8,804	8,454
Net income	317	333
Other comprehensive income	0	0
Common stock dividends declared	(170)	(147)
Dividends declared on preferred and preference stock	(30)	(28)
Stock-based compensation	(34)	(22)
Non-cash stock-based compensation	0	0
Issuance of preference stock	0
Redemption of preference stock	(3)
Balance, at the end of the period	8,884	8,590
Southern California Edison | Preferred and preference stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance, at the beginning of the period	2,070	2,070
Other comprehensive income	0	0
Common stock dividends declared	0	0
Dividends declared on preferred and preference stock	0	0
Stock-based compensation	0	0
Non-cash stock-based compensation	0	0
Issuance of preference stock	300
Redemption of preference stock	(125)
Balance, at the end of the period	$ 2,245	$ 2,070