PROPERTY, PLANT AND EQUIPMENT (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	$ 146,794	$ 114,907
Accumulated depreciation	(79,743)	(74,011)
Property, plant and equipment, net	67,051	40,896
Power Solutions [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, net	28,200
Land [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	3,315	3,229
Buildings and Improvements [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	31,156	25,216
Machinery and Equipment [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	107,032	82,420
Construction in Progress [Member]
Property, plant and equipment [Abstract]
Property, plant and equipment, gross	$ 5,291	$ 4,042