VALUATION AND QUALIFYING ACCOUNTS (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		$ 2,553	$ 10,605	$ 15,351
Charged to Costs and Expenses		1,441	6,021	(2,958)
Net (Deductions) Recoveries	[1]	477	(14,073)	(1,788)
Balance at End of Period		4,471	2,553	10,605
Deferred tax asset valuation allowance
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		356	276	2
Charged to Costs and Expenses	[2]	3,638	80	274
Net (Deductions) Recoveries		0	0	0
Balance at End of Period		3,994	356	276
Reserve for obsolete or slow moving inventory
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period		3,052	2,588	651
Charged to Costs and Expenses		5,869	6,401	2,272
Net (Deductions) Recoveries	[3]	(5,046)	(5,937)	(335)
Balance at End of Period		$ 3,875	$ 3,052	$ 2,588

[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.