CALIFORNIA UTILITIES' REGULATORY MATTERS - MAJOR PROJECTS UPDATES (Details) $ in Millions	9 Months Ended
	Sep. 30, 2016 USD ($)	Oct. 31, 2016 USD ($)	Aug. 31, 2016 project MW
Southern Gas System Member [Member]
Public Utilities, General Disclosures [Line Items]
Impairment charge after tax	$ 13
Impairment charge pre-tax	22
Pipeline Safety And Reliability Project [Member]
Public Utilities, General Disclosures [Line Items]
Revised estimated project cost	633
San Diego Gas and Electric Company [Member] | Cleveland National Forest Transmissions Projects [Member]
Public Utilities, General Disclosures [Line Items]
Estimated project cost	680
San Diego Gas and Electric Company [Member] | Cleveland National Forest Projects Transmission Level Facilities [Member]
Public Utilities, General Disclosures [Line Items]
Estimated project cost	470
San Diego Gas and Electric Company [Member] | Cleveland National Forest Projects Distribution Level Facilities [Member]
Public Utilities, General Disclosures [Line Items]
Estimated project cost	210
San Diego Gas and Electric Company [Member] | Energy Storage Projects [Member]
Public Utilities, General Disclosures [Line Items]
Number of Projects | project			2
Energy Storage Capacity | MW			37.5
San Diego Gas and Electric Company [Member] | Maximum [Member] | Sycamore Penasquitos Transmission Project [Member] | Subsequent Event [Member]
Public Utilities, General Disclosures [Line Items]
Estimated project cost		$ 260
San Diego Gas and Electric Company [Member] | Maximum [Member] | South Orange County Reliability Enhancement [Member]
Public Utilities, General Disclosures [Line Items]
Estimated project cost	$ 381