ACCOUNTS RECEIVABLE (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable
Accounts receivable, gross				$ 90,000	$ 61,000
Retail, Allowance for Credit Losses	$ (5,716)	$ (5,000)	$ (5,000)	(13,260)	(5,716)
Accounts Receivable				173,412	154,847
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning of Period	(5,716)	(5,000)	(5,000)
Credit Loss Expense	(10,000)	(4,000)	(3,000)
Write-offs	3,000	3,000	3,000
End of Period	(13,260)	$ (5,716)	$ (5,000)
Service disconnection moratoriums, increase in bad debt reserve	$ 7,000
Retail, Unbilled
Accounts Receivable
Accounts receivable, gross				41,000	42,000
Wholesale
Accounts Receivable
Accounts receivable, gross				33,000	31,000
Wholesale | Derivatives
Accounts Receivable
Accounts receivable, gross				7,000	5,000
Trade Accounts | Due from Affiliates
Accounts Receivable
Accounts receivable, gross				9,000	8,000
Other
Accounts Receivable
Accounts receivable, gross				$ 13,000	$ 19,000