Supplemental Cash Flows Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash payments for interest and taxes:
Interest, net of amounts capitalized	$ 164	$ 167
Tax refunds	(93)	0
Common stock
Dividends declared but not paid:
Dividends declared but not paid	197	177
Preferred and preference stock
Dividends declared but not paid:
Dividends declared but not paid	1	1
Southern California Edison
Cash payments for interest and taxes:
Interest, net of amounts capitalized	149	152
Tax refunds	(18)	0
Dividends declared but not paid:
Accrued capital expenditures	399	275
Southern California Edison | Common stock
Dividends declared but not paid:
Dividends declared but not paid	212	0
Southern California Edison | Preferred and preference stock
Dividends declared but not paid:
Dividends declared but not paid	$ 1	$ 1