OTHER CONTINGENCIES AND COMMITMENTS (Order Instituting Investigation Legal Obligation) (Details) - Pacific Gas & Electric Co $ in Millions	Sep. 30, 2020 USD ($)
Loss Contingencies [Line Items]
Expense	$ 1,222
Capital	403
Expenses and capital expenditures, forecast	1,625
Distribution Safety Inspections and Repairs Expense (FRMMA/WMPMA)
Loss Contingencies [Line Items]
Expense	236
Capital	0
Total	236
Expenses and capital expenditures, forecast	29
Transmission Safety Inspections and Repairs Expense (TO)
Loss Contingencies [Line Items]
Expense	433
Capital	0
Total	433
Vegetation Management Support Costs (FHPMA)
Loss Contingencies [Line Items]
Expense	36
Capital	0
Total	36
2017 Northern California Wildfires CEMA Expense and Capital (CEMA)
Loss Contingencies [Line Items]
Expense	82
Capital	66
Total	148
2018 Camp Fire CEMA Expense (CEMA)
Loss Contingencies [Line Items]
Expense	435
Capital	0
Total	435
2018 Camp Fire CEMA Capital for Restoration (CEMA)
Loss Contingencies [Line Items]
Expense	0
Capital	253
Total	253
2018 Camp Fire CEMA Capital for Temporary Facilities (CEMA)
Loss Contingencies [Line Items]
Expense	0
Capital	84
Total	84
Expenses and capital expenditures, forecast	$ 59