DERIVATIVE FINANCIAL INSTRUMENTS - DERIVATIVE NOTIONALS (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Interest rate and foreign exchange instruments [Member]
Derivative [Line Items]
Notional amount of derivative	$ 306	$ 306
Foreign Exchange [Member]
Derivative [Line Items]
Notional amount of derivative	1,060	1,158
Cash Flow Hedging [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Notional amount of derivative	1,433	594
San Diego Gas and Electric Company [Member] | Swaption [Member]
Derivative [Line Items]
Notional amount of derivative	142
San Diego Gas and Electric Company [Member] | Cash Flow Hedging [Member] | Interest Rate Contract [Member]
Derivative [Line Items]
Notional amount of derivative	$ 159	$ 142