OTHER CONTINGENCIES AND COMMITMENTS (Natural Gas Compressor Station Sites) (Details) $ in Millions	Sep. 30, 2020 USD ($)
Topock Site
Long-term Purchase Commitment [Line Items]
Amount of environmental loss actual expected to be recovered	$ 221
Topock Site | Pacific Gas & Electric Co
Long-term Purchase Commitment [Line Items]
Remediation cost recovery percentage	90.00%
Hinkley Natural Gas Compressor Station
Long-term Purchase Commitment [Line Items]
Amount of environmental loss actual expected to be recovered	$ 137
Former Manufactured Gas Plant
Long-term Purchase Commitment [Line Items]
Amount of environmental loss actual expected to be recovered	$ 492
Remediation cost recovery percentage	90.00%
Utility Owned Generation Facilities and Third Party Disposal Sites
Long-term Purchase Commitment [Line Items]
Amount of environmental loss actual expected to be recovered	$ 64
Utility Owned Generation Facilities and Third Party Disposal Sites | Pacific Gas & Electric Co
Long-term Purchase Commitment [Line Items]
Remediation cost recovery percentage	90.00%
Fossil Fuel Fired Generation
Long-term Purchase Commitment [Line Items]
Amount of environmental loss actual expected to be recovered	$ 40