SEGMENT AND GEOGRAPHICAL REPORTING - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Identifiable assets at year end	$ 788,220	$ 699,962
Depreciation	10,100	9,578	$ 10,520
Corporate
Segment Reporting Information [Line Items]
Capital expenditures	9,500	600	200
Identifiable assets at year end	56,800	54,700	19,400
Depreciation	$ 1,700	$ 1,500	$ 1,800