OTHER CONTINGENCIES AND COMMITMENTS - 2022 Cost of Capital Application (Details) $ in Millions	6 Months Ended
	Jun. 30, 2022 USD ($)	Sep. 30, 2021
Loss Contingencies [Line Items]
Annual cost of capital adjustment, indicator	4.50%
Annual cost of capital adjustment, basis point maximum	100
Proposed cost of long-term debt	4.14%
Proposed return on preferred stock	5.52%
Proposed return on equity	11.00%
Annual cost of capital adjustment, indicator, basis point		117
Decrease in jurisdictional revenue requirement	$ 163
Electric
Loss Contingencies [Line Items]
Decrease in jurisdictional revenue requirement	99
Natural gas
Loss Contingencies [Line Items]
Decrease in jurisdictional revenue requirement	$ 64
Extraordinary Circumstances
Loss Contingencies [Line Items]
Cost of long-term debt	4.17%
Return on preferred equity	5.52%
Return on equity	10.25%
Not Extraordinary Circumstances
Loss Contingencies [Line Items]
Cost of long-term debt	5.52%
Return on preferred equity	9.67%
Return on equity	4.15%