EMPLOYEE BENEFIT PLANS (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) noncallable_bond	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Assumed health care cost trend rate	6.50%
Ultimate trend rate	4.50%
Assumed return	6.00%
10 year actual rate of return	10.00%
Number of Aa-grade non-callable bonds used to develop the yield curve for rate used (noncallable bond) | noncallable_bond	1,101
Total fair value of trust other net liabilities	$ (22)
Total fair value of trust other net assets		$ 116
Retirement savings plan expense	$ 105	$ 103	$ 97
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
10 year actual rate of return	6.00%	6.20%	5.30%
Company contributions	$ 334	$ 335
Expected employer contribution next year	327
PBOP Plans
Defined Benefit Plan Disclosure [Line Items]
Company contributions	31	33
Expected employer contribution next year	24
Pacific Gas & Electric Co | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Public utilities, approved rate, amount	$ 327	$ 327