SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Schedule of Estimated Useful Lives and Balances of Utility's Property, Plant and Equipment) (Details) - Pacific Gas & Electric Co - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Public Utility, Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	$ 83,270	$ 77,245
Accumulated depreciation	(24,713)	(23,456)
Net property, plant, and equipment	58,557	53,789
Electricity generating facilities
Public Utility, Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	$ 13,047	11,843
Electricity generating facilities | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	5 years
Electricity generating facilities | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	120 years
Electricity distribution facilities
Public Utility, Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	$ 32,926	31,110
Electricity distribution facilities | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	15 years
Electricity distribution facilities | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	65 years
Electricity transmission facilities
Public Utility, Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	$ 13,177	12,180
Electricity transmission facilities | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	15 years
Electricity transmission facilities | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	75 years
Natural gas distribution facilities
Public Utility, Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	$ 13,296	12,312
Natural gas distribution facilities | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	20 years
Natural gas distribution facilities | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	60 years
Natural gas transmission and storage facilities
Public Utility, Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	$ 8,260	7,329
Natural gas transmission and storage facilities | Minimum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	5 years
Natural gas transmission and storage facilities | Maximum
Public Utility, Property, Plant and Equipment [Line Items]
Estimated Useful Lives (years)	62 years
Construction work in progress
Public Utility, Property, Plant and Equipment [Line Items]
Total property, plant, and equipment	$ 2,564	$ 2,471