SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Revenues Disaggregated by Type of Customer) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accounting Policies [Abstract]
Period for probable revenue recovery			24 months
Pacific Gas & Electric Co
Revenue from contracts with customers
Total operating revenues	$ 4,533	$ 3,943	$ 8,839	$ 7,954
Pacific Gas & Electric Co | Electric
Revenue from contracts with customers
Total revenue from contracts with customers	3,058	2,732	5,722	5,060
Regulatory balancing accounts	377	214	753	678
Total operating revenues	3,435	2,946	6,475	5,738
Pacific Gas & Electric Co | Electric | Residential
Revenue from contracts with customers
Total revenue from contracts with customers	987	994	2,230	2,282
Pacific Gas & Electric Co | Electric | Commercial
Revenue from contracts with customers
Total revenue from contracts with customers	1,075	1,135	2,082	2,088
Pacific Gas & Electric Co | Electric | Industrial
Revenue from contracts with customers
Total revenue from contracts with customers	342	326	682	619
Pacific Gas & Electric Co | Electric | Agricultural
Revenue from contracts with customers
Total revenue from contracts with customers	368	261	491	347
Pacific Gas & Electric Co | Electric | Public street and highway lighting
Revenue from contracts with customers
Total revenue from contracts with customers	17	16	34	33
Pacific Gas & Electric Co | Electric | Other
Revenue from contracts with customers
Total revenue from contracts with customers	269	0	203	(309)
Pacific Gas & Electric Co | Natural gas
Revenue from contracts with customers
Total revenue from contracts with customers	673	647	2,299	2,365
Regulatory balancing accounts	425	350	65	(149)
Total operating revenues	1,098	997	2,364	2,216
Pacific Gas & Electric Co | Natural gas | Residential
Revenue from contracts with customers
Total revenue from contracts with customers	426	343	1,492	1,515
Pacific Gas & Electric Co | Natural gas | Commercial
Revenue from contracts with customers
Total revenue from contracts with customers	110	129	344	369
Pacific Gas & Electric Co | Natural gas | Transportation service only
Revenue from contracts with customers
Total revenue from contracts with customers	296	304	643	686
Pacific Gas & Electric Co | Natural gas | Other
Revenue from contracts with customers
Total revenue from contracts with customers	$ (159)	$ (129)	$ (180)	$ (205)