OTHER CONTINGENCIES AND COMMITMENTS (Transmission Owner Rate) (Details) $ in Millions	Jul. 22, 2021 petition	Sep. 21, 2018	Jun. 21, 2021 petition	Apr. 15, 2021 USD ($) party	May 21, 2020
Transmission Owner Rate Case Revenue
Loss Contingencies [Line Items]
Approved depreciation rate					2.94%
Requested depreciation rate					3.25%
Labor rates, allocation percentage					6.15%
Direct assignment, percentage					8.84%
Number of petitions for review to be consolidated (petition) | petition			2
Regulatory liabilities | $				$ 274
Regulatory assets | $				$ 150
Transmission Owner Rate Case Revenue | Subsequent event
Loss Contingencies [Line Items]
Number of petitions for review to be consolidated (petition) | petition	2
Petition review, pending substantive order duration	75 days
Pacific Gas & Electric Co (Utility) | Transmission Owner Rate Case Revenue
Loss Contingencies [Line Items]
Number of parties granted for rehearing related to Tax Act | party				2
Pacific Gas & Electric Co (Utility) | Electric
Loss Contingencies [Line Items]
Requested revenue rate		98.85%