ACCOUNTS RECEIVABLE (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, gross		$ 52,000	$ 61,000
Allowance for Credit Losses	$ (5,698)	(5,698)	(5,716)
Accounts Receivable, Net		124,738	154,847
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning of Period	(5,716)
Credit Loss Expense	(1,000)
Write-offs	1,000
End of Period	$ (5,698)
Unbilled
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, gross		32,000	42,000
Trade Accounts | Due from Affiliates
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, gross		11,000	8,000
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, gross		14,000	19,000
Wholesale
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, gross		22,000	31,000
Wholesale | Derivatives
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, gross		$ 5,000	$ 5,000