ESTIMATES, SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND BALANCE SHEET DETAIL Estimates, Significant Accounting Policies and Balance Sheet Detail - Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Other Liabilities, Current [Abstract]
Customer Advances and Deposits, Current	$ 8,000	$ 13,000
Accrued Liabilities and Other Liabilities	13,000	21,000
Accrued Capital Expenditures	4,000	11,000
Taxes Payable, Current	0	16,000
Asset Retirement Obligation, Current	0	5,000
Other Accrued Liabilities	8,000	9,000
Other current liabilities	$ 33,000	$ 75,000