EMPLOYEE BENEFIT PLANS (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($) noncallable_bond	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Assumed health care cost trend rate	6.30%
Ultimate trend rate	4.50%
Assumed return	5.70%
10 year actual rate of return	9.30%
Number of Aa-grade non-callable bonds used to develop the yield curve for rate used (noncallable bond) | noncallable_bond	936
Total fair value of trust other net liabilities	$ 99	$ 99
Total fair value of trust other net assets	22	22
Retirement savings plan expense	$ 109	$ 105	$ 103
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
10 year actual rate of return	5.70%	6.00%	6.20%
Company contributions	$ 328	$ 334
Expected employer contribution next year	327
PBOP Plans
Defined Benefit Plan Disclosure [Line Items]
Company contributions	29	31
Expected employer contribution next year	15
Pacific Gas & Electric Co | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Public utilities, approved rate, amount	$ 328	$ 328