SCHEDULE II -VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Year	$ 22,299	$ 17,255	$ 40,670
Additions Charged to Costs and Expenses		5,044
Deductions	(6,391)		(23,415)
Balance at End of Year	15,908	22,299	17,255
Allowance for inventory obsolescence
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Year	22,141	17,098	40,497
Additions Charged to Costs and Expenses		5,043
Deductions	(6,251)		(23,399)
Balance at End of Year	15,890	22,141	17,098
Allowance for doubtful accounts receivable
VALUATION AND QUALIFYING ACCOUNTS
Balance at Beginning of Year	158	157	173
Additions Charged to Costs and Expenses		1
Deductions	(140)		(16)
Balance at End of Year	$ 18	$ 158	$ 157