WILDFIRE-RELATED CONTINGENCIES (Potential Losses in Connection with the 2018 Camp Fire and 2017 Northern California Wildfires) (Details) insurance_claim in Thousands			3 Months Ended		9 Months Ended	12 Months Ended
	May 08, 2019 USD ($)	Sep. 06, 2018 USD ($) insurance_claim	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2015 USD ($)	Oct. 17, 2019 USD ($)
2017 Northern California wildfires
Loss Contingencies [Line Items]
Total insurance claims received by insurers		$ 12,280,000,000
Insurance claims received by insurers (insurance claim) | insurance_claim		55
Statewide insurance claims related to wildfire		$ 10,000,000,000
Loss contingency liability			$ 7,500,000,000		$ 7,500,000,000
2018 Camp Fire
Loss Contingencies [Line Items]
Total insurance claims received by insurers	$ 8,600,000,000
Loss in period			526,000,000	$ 1,900,000,000	2,400,000,000	$ 10,500,000,000
Loss contingency liability			12,900,000,000		12,900,000,000
November 2018 Fires
Loss Contingencies [Line Items]
Total insurance claims received by insurers	$ 12,000,000,000
2018 Camp Fire and 2017 Northern California Wildfires
Loss Contingencies [Line Items]
Total insurance claims received by insurers		$ 18,600,000,000
Estimate of possible losses			30,000,000,000		30,000,000,000
2018 Camp Fire and 2017 Northern California Wildfires | Minimum
Loss Contingencies [Line Items]
Total insurance claims received by insurers					30,000,000,000
2018 Camp Fire and 2017 Northern California Wildfires | Maximum
Loss Contingencies [Line Items]
Total insurance claims received by insurers					40,000,000,000
Subsequent event | 2015 Butte Fire, 2017 Northern California Wildfires, and 2018 Camp Fire
Loss Contingencies [Line Items]
Estimate of possible losses								$ 13,500,000,000
Pacific Gas & Electric Co | San Bruno Natural Gas Explosion
Loss Contingencies [Line Items]
Loss in period							$ 1,600,000,000
Loss contingency liability							$ 558,000,000
FEMA | 2017 Northern California wildfires
Loss Contingencies [Line Items]
Amount of claims filed					1,200,000,000
FEMA | 2018 Camp Fire
Loss Contingencies [Line Items]
Amount of claims filed					2,600,000,000
Cal Fire | 2017 Northern California wildfires
Loss Contingencies [Line Items]
Amount of claims filed					133,000,000
Cal Fire | 2018 Camp Fire
Loss Contingencies [Line Items]
Amount of claims filed					110,000,000
OES | 2017 Northern California wildfires
Loss Contingencies [Line Items]
Amount of claims filed					347,000,000
OES | 2018 Camp Fire
Loss Contingencies [Line Items]
Amount of claims filed					2,300,000,000
California Department of Transportation | 2018 Camp Fire
Loss Contingencies [Line Items]
Amount of claims filed					217,000,000
The Ad Hoc Subrogation Group | 2018 Camp Fire and 2017 Northern California Wildfires
Loss Contingencies [Line Items]
Estimate of possible losses			$ 20,000,000,000		$ 20,000,000,000