CONTINGENCIES AND COMMITMENTS (Summary of Wildfire-Related Claims Reported on Consolidated Balance Sheets) (Details) - Pacific Gas & Electric Co - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Butte Fire And Northern California Wildfires
Loss Contingencies [Line Items]
Total wildfire-related claims	$ 2,860	$ 561
Butte Fire
Loss Contingencies [Line Items]
Total wildfire-related claims	360	561
Nothern California Wild Fire
Loss Contingencies [Line Items]
Total wildfire-related claims	$ 2,500	$ 0