SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Significant Accounting Policies [Line Items]
Number of natural gas distribution services customers	2,200,000
Unbilled Receivables, Current	$ 183,200	$ 144,900
Accounts Receivable, Allowance for Credit Loss, Current	18,700	16,600
Asset Impairment Charges	0	0	$ 0
Goodwill, Impairment Loss	0	0	$ 0
Deferred Tax Assets, Valuation Allowance	0	0
Liability for Uncertainty in Income Taxes, Current	$ 0	$ 0
Segment Reporting, Disclosure of Major Customer	0