WILDFIRE-RELATED CONTINGENCIES (2018 Camp Fire and 2017 Northern California Wildfires Accounting Charge) (Details) $ in Billions		3 Months Ended		12 Months Ended
	Dec. 11, 2018	Dec. 31, 2018 USD ($)	Jun. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)	Mar. 31, 2019 wildfire
2018 Camp fire
Loss Contingencies [Line Items]
Accrued losses				$ 10.5
2017 Northern California wildfires
Loss Contingencies [Line Items]
Number of fires with probable losses (wildfire) | wildfire					17
Loss from claims related to wildfire		$ 1.0	$ 2.5	$ 3.5
Pacific Gas & Electric Co | 2018 Camp fire
Loss Contingencies [Line Items]
Electric Incident Report, term	20 days