SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Revenues Disaggregated by Type of Customer) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Disaggregation of Revenue [Abstract]
Total operating revenues	$ 5,118	$ 5,215	$ 10,916	$ 9,931
Electric
Disaggregation of Revenue [Abstract]
Total operating revenues	3,690	3,951	7,848	7,346
Natural gas
Disaggregation of Revenue [Abstract]
Total operating revenues	1,428	1,264	3,068	2,585
Pacific Gas & Electric Co (Utility)
Disaggregation of Revenue [Abstract]
Total operating revenues	5,118	5,215	10,916	9,931
Pacific Gas & Electric Co (Utility) | Electric
Disaggregation of Revenue [Abstract]
Total operating revenues	3,213	3,574	6,451	6,483
Regulatory balancing accounts	477	377	1,397	863
Total operating revenues	3,690	3,951	7,848	7,346
Pacific Gas & Electric Co (Utility) | Electric | Residential
Disaggregation of Revenue [Abstract]
Total operating revenues	1,213	1,352	2,707	2,815
Pacific Gas & Electric Co (Utility) | Electric | Commercial
Disaggregation of Revenue [Abstract]
Total operating revenues	1,252	1,183	2,425	2,196
Pacific Gas & Electric Co (Utility) | Electric | Industrial
Disaggregation of Revenue [Abstract]
Total operating revenues	322	305	672	632
Pacific Gas & Electric Co (Utility) | Electric | Agricultural
Disaggregation of Revenue [Abstract]
Total operating revenues	484	431	700	583
Pacific Gas & Electric Co (Utility) | Electric | Public street and highway lighting
Disaggregation of Revenue [Abstract]
Total operating revenues	19	18	37	35
Pacific Gas & Electric Co (Utility) | Electric | Other
Disaggregation of Revenue [Abstract]
Total operating revenues	(77)	285	(90)	222
Pacific Gas & Electric Co (Utility) | Natural gas
Disaggregation of Revenue [Abstract]
Total operating revenues	853	766	2,880	2,498
Regulatory balancing accounts	575	498	188	87
Total operating revenues	1,428	1,264	3,068	2,585
Pacific Gas & Electric Co (Utility) | Natural gas | Residential
Disaggregation of Revenue [Abstract]
Total operating revenues	388	418	1,851	1,626
Pacific Gas & Electric Co (Utility) | Natural gas | Commercial
Disaggregation of Revenue [Abstract]
Total operating revenues	197	139	541	384
Pacific Gas & Electric Co (Utility) | Natural gas | Transportation service only
Disaggregation of Revenue [Abstract]
Total operating revenues	356	346	755	672
Pacific Gas & Electric Co (Utility) | Natural gas | Other
Disaggregation of Revenue [Abstract]
Total operating revenues	$ (88)	$ (137)	$ (267)	$ (184)