OTHER CONTINGENCIES AND COMMITMENTS (Order Instituting Investigation Narrative) (Details) - USD ($) $ in Millions		3 Months Ended
	Feb. 27, 2020	Mar. 31, 2020	Apr. 20, 2020	Mar. 27, 2020	Dec. 17, 2019
Loss Contingencies [Line Items]
Expenses and capital expenditures, disallowed capital, gross		$ 344
Expenses and capital expenditures, disallowed capital, net	$ 1,823	403
Expenses and capital expenditures, disallowed capital, expected charges to be recorded		59
Expenses and capital expenditures, modification, disallowed capital	198
Shareholder-funded system enhancement initiatives, modification	64
Fine payable to general fund	200
Fine payable to general fund, suspended				$ 200
Subsequent event
Loss Contingencies [Line Items]
Fine payable to general fund, suspended			$ 200
Expenses and capital expenditures, disallowed capital, approved			198
Shareholder-funded system enhancement initiatives, approved			$ 64
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		19
Expenses and capital expenditures, disallowed capital, charges recorded		71
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	$ 114				$ 50
Expenses and capital expenditures, difference		$ 1,420