OTHER CONTINGENCIES AND COMMITMENTS (Interim Rate Relief Subject to Refund) (Details) - WMCE Interim Rate Relief - USD ($) $ in Millions	Sep. 21, 2021	Jun. 30, 2022	Oct. 23, 2020	Sep. 30, 2020
Loss Contingencies [Line Items]
Expenses and capital expenditures, disallowed costs				$ 1,180
Expenses and capital expenditures, capital expenditures				801
Cost recovery, increase to revenue requirement				$ 1,280
Interim rate relief			$ 447
Cost recovery, remaining revenue requirement			$ 868
Additional revenue requirement	$ 591
Additional amortization period	24 months
Fire hazard prevention memorandum account
Loss Contingencies [Line Items]
Cost recovery		$ 293
Fire risk and wildfire mitigation memorandum account
Loss Contingencies [Line Items]
Cost recovery		740
Catastrophic event memorandum account
Loss Contingencies [Line Items]
Cost recovery		$ 251