GOODWILL AND OTHER INTANGIBLE ASSETS - Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
GOODWILL AND OTHER INTANGIBLE ASSETS
Definite-lived, Gross Carrying Amount	$ 36,913		$ 35,682
Definite-lived, Accumulated Amortization	(24,615)		(24,321)
Definite-lived, Net Carrying Amount	12,298		11,361
Total other intangible assets, Gross Carrying Amount	45,983		44,752
Total other intangible assets, Accumulated Impairment	(4,953)		(4,953)
Total other intangible assets, Net Carrying Amount	16,415		15,478
Amortization expense	1,200	$ 2,000
Trade name
GOODWILL AND OTHER INTANGIBLE ASSETS
Indefinite lived, Gross Carrying Amount	9,070		9,070
Indefinite lived, Accumulated Impairment	(4,953)		(4,953)
Indefinite lived, Net Carrying Amount	4,117		4,117
Customer lists
GOODWILL AND OTHER INTANGIBLE ASSETS
Definite-lived, Gross Carrying Amount	27,420		26,036
Definite-lived, Accumulated Amortization	(19,443)		(19,051)
Definite-lived, Net Carrying Amount	7,977		6,985
Trade name
GOODWILL AND OTHER INTANGIBLE ASSETS
Definite-lived, Gross Carrying Amount	255		255
Definite-lived, Accumulated Amortization	(132)		(125)
Definite-lived, Net Carrying Amount	123		130
Patents and other intangibles
GOODWILL AND OTHER INTANGIBLE ASSETS
Definite-lived, Gross Carrying Amount	9,238		9,391
Definite-lived, Accumulated Amortization	(5,040)		(5,145)
Definite-lived, Net Carrying Amount	$ 4,198		$ 4,246