WILDFIRE-RELATED CONTINGENCIES (Clean-up and Repair Costs) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Loss Contingencies [Line Items]
Capital expenditures	$ 326	$ 242
Total long-term regulatory assets	6,604		$ 6,066
Catastrophic event memorandum account
Loss Contingencies [Line Items]
Total long-term regulatory assets	684		656
Pacific Gas & Electric Co
Loss Contingencies [Line Items]
Capital expenditures	326	$ 242
Total long-term regulatory assets	6,604		$ 6,066
Pacific Gas & Electric Co | 2018 Camp Fire
Loss Contingencies [Line Items]
Service restoration and repair costs	786
Capital expenditures	327
Pacific Gas & Electric Co | 2017 Northern California wildfires
Loss Contingencies [Line Items]
Service restoration and repair costs	365
Capital expenditures	187
Pacific Gas & Electric Co | 2019 Kincade Fire
Loss Contingencies [Line Items]
Service restoration and repair costs	60
Capital expenditures	17
Pacific Gas & Electric Co | Catastrophic event memorandum account | 2018 Camp Fire
Loss Contingencies [Line Items]
Total long-term regulatory assets	0
Pacific Gas & Electric Co | Catastrophic event memorandum account | 2017 Northern California wildfires
Loss Contingencies [Line Items]
Total long-term regulatory assets	67
Pacific Gas & Electric Co | Catastrophic event memorandum account | 2019 Kincade Fire
Loss Contingencies [Line Items]
Total long-term regulatory assets	$ 34