PROPERTY, PLANT AND EQUIPMENT (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Accumulated depreciation	$ (49,194)	$ (47,635)
Property, plant and equipment, net	82,285	80,679
Outside United States [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	24,200	23,700
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,729	2,715
Building and Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	43,451	43,190
Furniture and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	71,280	70,874
Sub-total [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	117,460	116,779
Property, Plant and Equipment Placed in Service, Net [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	68,266	69,144
Construction in Progress [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 14,019	$ 11,535