Regulatory Assets and Liabilities (Regulatory Balancing Accounts) (Details) (Southern California Edison, USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Regulatory balancing accounts | Energy resource recovery account
Regulatory Assets and Liabilities
Net liability	$ 1,617	$ 1,005
Regulatory balancing accounts | Four Corners memorandum account
Regulatory Assets and Liabilities
Net liability	4	145
Regulatory balancing accounts | New system generation balancing account
Regulatory Assets and Liabilities
Net liability	50	132
Refunds of excess revenue | Significant Components
Regulatory Assets and Liabilities
Net liability	(48)	(554)
Refunds of excess revenue | Public purpose programs and energy efficiency programs
Regulatory Assets and Liabilities
Net liability	(850)	(1,037)
Refunds of excess revenue | Base rate recovery balancing account
Regulatory Assets and Liabilities
Net liability	(103)	(247)
Refunds of excess revenue | Greenhouse gas auction revenue
Regulatory Assets and Liabilities
Net liability	(310)	(385)
Refunds of excess revenue | FERC formula rates and FERC balancing accounts
Regulatory Assets and Liabilities
Net liability	(63)	(59)
Refunds of excess revenue | FERC energy settlements
Regulatory Assets and Liabilities
Net liability	(179)	0
Refunds of excess revenue | Other
Regulatory Assets and Liabilities
Net liability	$ (214)	$ (108)