INCOME TAXES (Schedule of Change in Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pacific Gas & Electric Co
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance, beginning of period	$ 377	$ 349	$ 382
Reductions for tax position taken during a prior year	(1)	(27)	(71)
Additions for tax position taken during the current year	44	55	48
Settlements	0	0	(8)
Expiration of statute	0	0	(3)
Balance, end of period	420	377	349
PG&E Corporation
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance, beginning of period	377	349	388
Reductions for tax position taken during a prior year	(1)	(27)	(71)
Additions for tax position taken during the current year	44	55	48
Settlements	0	0	(14)
Expiration of statute	0	0	(3)
Balance, end of period	$ 420	$ 377	$ 349