INCOME TAXES (Schedule of Income Tax Provision (Benefit)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current:
Federal	$ (26)	$ 1	$ (5)
State	(34)	101	(8)
Deferred:
Federal	258	(2,361)	(2,264)
State	171	(1,136)	(1,009)
Tax credits	(7)	(5)	(6)
Income tax provision (benefit)	362	(3,400)	(3,292)
Pacific Gas & Electric Co (Utility)
Current:
Federal	(26)	4	5
State	(34)	94	(7)
Deferred:
Federal	290	(2,363)	(2,278)
State	185	(1,137)	(1,009)
Tax credits	(7)	(5)	(6)
Income tax provision (benefit)	$ 408	$ (3,407)	$ (3,295)