OTHER CONTINGENCIES AND COMMITMENTS (Order Instituting Investigation Narrative) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020 USD ($)	Jun. 08, 2020 party	Apr. 20, 2020 USD ($)	Dec. 17, 2019 USD ($)
Loss Contingencies [Line Items]
Expenses and capital expenditures, disallowed capital, gross	$ 348
Expenses and capital expenditures, disallowed capital, net	403
Expenses and capital expenditures, disallowed capital, expected charges to be recorded	34
Expenses and capital expenditures, disallowed capital, approved			$ 198
Shareholder-funded system enhancement initiatives, approved			64
Fine payable to general fund, suspended			$ 200
Number of parties filed separate applications for rehearing | party		2
Pacific Gas & Electric Co | Vegetation Management Support Costs (FHPMA)
Loss Contingencies [Line Items]
Expenses and capital expenditures	36
Expenses and capital expenditures, disallowed capital, expected charges to be recorded	6
Expenses and capital expenditures, disallowed capital, charges recorded	84
Pacific Gas & Electric Co | Pending Litigation | Unfavorable Regulatory Action
Loss Contingencies [Line Items]
Expenses and capital expenditures	1,625			$ 1,625
Shareholder-funded system enhancement initiatives, amount				$ 50
Expenses and capital expenditures, difference	$ 1,420