DERIVATIVE FINANCIAL INSTRUMENTS - DERIVATIVE INSTRUMENTS WITH CONTINGENT FEATURES (Details) - USD ($) $ in Millions	Sep. 30, 2016	Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Net liability position for derivatives with credit limits	$ 6	$ 6
Additional collateral that wil be required if credit rating falls below investment grade	8
San Diego Gas and Electric Company [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net liability position for derivatives with credit limits	3	$ 5
Additional collateral that wil be required if credit rating falls below investment grade	$ 5