CALIFORNIA UTILITIES' REGULATORY MATTERS - NATURAL GAS PIPELINE OPERATIONS SAFETY ASSESSMENTS (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2014	Oct. 31, 2016	Jun. 11, 2014
Southern California Gas Company [Member] | Pipeline Safety Enhancement Plan [Member]
Public Utilities, General Disclosures [Line Items]
Disallowed costs impact on earnings after tax		$ 5.0
Pipeline safety plan regulatory account	$ 212.0
Recovery requested, PSEP costs	180.5			$ 46.0
Southern California Gas Company [Member] | Pipeline Safety Enhancement Plan [Member] | Subsequent Event [Member]
Public Utilities, General Disclosures [Line Items]
Recovery requested, PSEP costs			$ 2.0
Southern California Gas Company [Member] | Pipeline Safety Enhancement Plan [Member] | Deferred Project Costs [Member] | Subsequent Event [Member]
Public Utilities, General Disclosures [Line Items]
Pipeline safety plan regulatory account			33.1
Southern California Gas Company [Member] | Pipeline Testing/Replacing 1956 to 1961 [Member]
Public Utilities, General Disclosures [Line Items]
Disallowed costs impact on earnings after tax	3.6
San Diego Gas and Electric Company [Member] | Pipeline Safety Enhancement Plan [Member]
Public Utilities, General Disclosures [Line Items]
Pipeline safety plan regulatory account	18.0
Recovery requested, PSEP costs	14.9			$ 0.1
San Diego Gas and Electric Company [Member] | Pipeline Safety Enhancement Plan [Member] | Subsequent Event [Member]
Public Utilities, General Disclosures [Line Items]
Recovery requested, PSEP costs			2.0
San Diego Gas and Electric Company [Member] | Pipeline Safety Enhancement Plan [Member] | Deferred Project Costs [Member] | Subsequent Event [Member]
Public Utilities, General Disclosures [Line Items]
Pipeline safety plan regulatory account			$ 0.1
San Diego Gas and Electric Company [Member] | Pipeline Testing/Replacing 1956 to 1961 [Member]
Public Utilities, General Disclosures [Line Items]
Disallowed costs impact on earnings after tax	$ 0.5