VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		$ 4,471	$ 2,553	$ 10,605
Charged to Costs and Expenses		588	1,441	6,021
Net (Deductions) Recoveries	[1]	(246)	477	(14,073)
Balance at End of Period		4,813	4,471	2,553
Deferred tax asset valuation allowance
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		3,994	356	276
Charged to Costs and Expenses	[2]	0	3,638	80
Net (Deductions) Recoveries		(3,549)	0	0
Balance at End of Period		445	3,994	356
Reserve for obsolete or slow moving inventory
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		3,875	3,052	2,588
Charged to Costs and Expenses		8,088	5,869	6,401
Net (Deductions) Recoveries	[3]	(1,794)	(5,046)	(5,937)
Balance at End of Period		$ 10,169	$ 3,875	$ 3,052

[1] Net (deductions) recoveries in the allowance for doubtful accounts principally reflect the write-off of previously reserved accounts net of recoveries.

[2] The valuation allowance for deferred tax assets is increased or decreased each year to reflect the state net operating losses, foreign tax credits and capital losses that management believes will not be utilized before they expire.

[3] Net (deductions) recoveries in the reserve for obsolete or slow moving inventory principally reflect the write-off and/ or disposal of previously reserved inventory.