INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 19, 2018	Dec. 31, 2017
Intangible assets subject to amortization
Gross Amount	$ 54,120			$ 50,043
Accumulated amortization	(18,997)			(17,970)
Net Book Value	35,123			32,073
Intangible assets resulting from acquisition			$ 3,700
Amortization expense for intangible assets	884	$ 793
Estimated amortization expense
Remainder of 2018	2,655
2019	3,540
2020	3,540
2021	3,266
2022	3,266
2023	3,184
Thereafter	15,672
Total estimated amortization expense	35,123
Customer lists
Intangible assets subject to amortization
Gross Amount	42,548			38,659
Accumulated amortization	(13,452)			(12,721)
Net Book Value	$ 29,096			25,938
Customer lists | Minimum
Intangible assets subject to amortization
Estimated Life	8 years
Customer lists | Maximum
Intangible assets subject to amortization
Estimated Life	17 years
Trade name
Intangible assets subject to amortization
Gross Amount	$ 6,255			6,213
Accumulated amortization	(2,932)			(2,798)
Net Book Value	$ 3,323			3,415
Trade name | Minimum
Intangible assets subject to amortization
Estimated Life	10 years
Trade name | Maximum
Intangible assets subject to amortization
Estimated Life	12 years
Design and technologies
Intangible assets subject to amortization
Gross Amount	$ 5,293			5,147
Accumulated amortization	(2,604)			(2,443)
Net Book Value	$ 2,689			2,704
Design and technologies | Minimum
Intangible assets subject to amortization
Estimated Life	10 years
Design and technologies | Maximum
Intangible assets subject to amortization
Estimated Life	12 years
Patents
Intangible assets subject to amortization
Gross Amount	$ 24			24
Accumulated amortization	(9)			(8)
Net Book Value	$ 15			$ 16
Estimated Life	17 years