OTHER CONTINGENCIES AND COMMITMENTS (Environmental Remediation Contingencies Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Long-term Purchase Commitment [Line Items]
Amount of environmental loss accrual expected to be recovered	$ 998
Pacific Gas & Electric Co
Long-term Purchase Commitment [Line Items]
Utility undiscounted future costs	20,560	$ 14,226
Topock Site
Long-term Purchase Commitment [Line Items]
Utility undiscounted future costs	$ 207
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]
Utility undiscounted future costs	$ 129
Former Manufactured Gas Plant
Long-term Purchase Commitment [Line Items]
Utility undiscounted future costs	$ 621
Remediation cost recovery percentage	90.00%
Utility Owned Generation Facilities and Third Party Disposal Sites
Long-term Purchase Commitment [Line Items]
Utility undiscounted future costs	$ 91
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]
Utility undiscounted future costs	$ 80