INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Jan. 12, 2016	Dec. 31, 2015
Intangible assets subject to amortization
Gross Amount	$ 48,460			$ 41,137
Accumulated amortization	(12,053)			(11,153)
Total estimated amortization expense	36,407			29,984
Amortization expense for intangible assets	779	$ 662
Estimated amortization expense
Remainder of 2016	2,346
2017	3,128
2018	3,128
2019	3,128
2020	3,128
Thereafter	21,549
Total estimated amortization expense	36,407			29,984
Heidrive
Intangible assets subject to amortization
Intangible assets acquired from the acquisition			$ 6,841
Customer lists
Intangible assets subject to amortization
Gross Amount	37,639			34,149
Accumulated amortization	(8,435)			(7,785)
Total estimated amortization expense	29,204			26,364
Estimated amortization expense
Total estimated amortization expense	$ 29,204			26,364
Customer lists | Minimum
Intangible assets subject to amortization
Estimated Life	8 years
Customer lists | Maximum
Intangible assets subject to amortization
Estimated Life	15 years
Trade name
Intangible assets subject to amortization
Gross Amount	$ 6,025			4,775
Accumulated amortization	(1,909)			(1,793)
Total estimated amortization expense	4,116			2,982
Estimated amortization expense
Total estimated amortization expense	$ 4,116			2,982
Trade name | Minimum
Intangible assets subject to amortization
Estimated Life	10 years
Trade name | Maximum
Intangible assets subject to amortization
Estimated Life	15 years
Design and technologies
Intangible assets subject to amortization
Gross Amount	$ 4,772			2,189
Accumulated amortization	(1,703)			(1,570)
Total estimated amortization expense	3,069			619
Estimated amortization expense
Total estimated amortization expense	$ 3,069			619
Design and technologies | Minimum
Intangible assets subject to amortization
Estimated Life	8 years
Design and technologies | Maximum
Intangible assets subject to amortization
Estimated Life	15 years
Patents
Intangible assets subject to amortization
Gross Amount	$ 24			24
Accumulated amortization	(6)			(5)
Total estimated amortization expense	18			19
Estimated amortization expense
Total estimated amortization expense	$ 18			$ 19