NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Additional Information) (Details) customer in Thousands	12 Months Ended
	Dec. 31, 2021 mi² customer
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of retail customers | customer	438
Area in which subsidiary generates transmits and distributes electricity to retail electric customers (sq miles) | mi²	1,155
Minimum
Regulatory Assets [Line Items]
Contracts, payment terms	10 days
Maximum
Regulatory Assets [Line Items]
Contracts, payment terms	20 days
Cloud Computing | Minimum
Regulatory Assets [Line Items]
Amortization period	3 years
Cloud Computing | Maximum
Regulatory Assets [Line Items]
Amortization period	5 years