INTANGIBLE ASSETS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jan. 12, 2016	Dec. 31, 2015
Intangible assets subject to amortization
Gross Amount	$ 49,095		$ 49,095			$ 41,137
Accumulated amortization	(12,807)		(12,807)			(11,153)
Total estimated amortization expense	36,288		36,288			29,984
Amortization expense for intangible assets	828	$ 660	1,607	$ 1,322
Estimated amortization expense
Remainder of 2016	1,602		1,602
2017	3,204		3,204
2018	3,204		3,204
2019	3,204		3,204
2020	3,204		3,204
Thereafter	21,870		21,870
Total estimated amortization expense	36,288		36,288			29,984
Heidrive
Intangible assets subject to amortization
Intangible assets acquired from the acquisition					$ 7,710
Customer lists
Intangible assets subject to amortization
Gross Amount	38,183		38,183			34,149
Accumulated amortization	(8,996)		(8,996)			(7,785)
Total estimated amortization expense	29,187		29,187			26,364
Estimated amortization expense
Total estimated amortization expense	29,187		$ 29,187			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	6,108		$ 6,108			4,775
Accumulated amortization	(2,040)		(2,040)			(1,793)
Total estimated amortization expense	4,068		4,068			2,982
Estimated amortization expense
Total estimated amortization expense	4,068		$ 4,068			2,982
Trade name | Minimum
Intangible assets subject to amortization
Estimated Life			10 years
Trade name | Maximum
Intangible assets subject to amortization
Estimated Life			17 years
Design and technologies
Intangible assets subject to amortization
Gross Amount	4,780		$ 4,780			2,189
Accumulated amortization	(1,765)		(1,765)			(1,570)
Total estimated amortization expense	3,015		3,015			619
Estimated amortization expense
Total estimated amortization expense	3,015		$ 3,015			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			24
Accumulated amortization	(6)		(6)			(5)
Total estimated amortization expense	18		18			19
Estimated amortization expense
Total estimated amortization expense	$ 18		$ 18			$ 19