INTANGIBLE ASSETS - Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Definite-lived intangible assets
Gross value of definite-lived intangible assets	$ 63,482	$ 63,552
Accumulated amortization	(40,455)	(39,557)
Net definite-lived intangible assets	23,027	23,995
Indefinite-lived intangible assets
Total intangible assets, net	24,332	25,300
Trademarks and trade names
Indefinite-lived intangible assets
Trademarks and trade names	1,305	1,305
Customer relationships
Definite-lived intangible assets
Gross value of definite-lived intangible assets	24,414	24,440
Accumulated amortization	(18,886)	(18,616)
Unpatented technology
Definite-lived intangible assets
Gross value of definite-lived intangible assets	14,884	14,917
Accumulated amortization	(5,609)	(5,245)
Patented technology
Definite-lived intangible assets
Gross value of definite-lived intangible assets	2,596	2,598
Accumulated amortization	(2,507)	(2,476)
Tradename
Definite-lived intangible assets
Gross value of definite-lived intangible assets	12,350	12,372
Accumulated amortization	(4,400)	(4,257)
All other
Definite-lived intangible assets
Gross value of definite-lived intangible assets	9,238	9,225
Accumulated amortization	$ (9,053)	$ (8,963)

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
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-Section 50
-Paragraph 2
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Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

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Amount of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit.

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Sum of the carrying amounts of all intangible assets, excluding goodwill, as of the balance sheet date, net of accumulated amortization and impairment charges.

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