SEGMENT AND GEOGRAPHIC DATA Geographic Data Reporting (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Revenue	$ 66,932	$ 59,615
Total assets	53,179	111,640
Net assets	40,487	43,152	$ 41,885
Net Assets	39,661	7,883
Hudson Americas
Segment Reporting Information [Line Items]
Revenue	13,944	16,243
Hudson Asia Pacific
Segment Reporting Information [Line Items]
Revenue	36,946	29,767
Hudson Europe
Segment Reporting Information [Line Items]
Revenue	16,062	13,652
Corporate
Segment Reporting Information [Line Items]
Revenue	0	0
Inter-segment elimination
Segment Reporting Information [Line Items]
Revenue	(20)	(47)
United Kingdom
Segment Reporting Information [Line Items]
Revenue	15,690	11,222
Net Assets	3,086	2,496
Australia
Segment Reporting Information [Line Items]
Revenue	30,181	24,973
Net Assets	3,101	1,671
United States
Segment Reporting Information [Line Items]
Revenue	12,949	15,405
Net Assets	28,595	1,605
Other [Domain]
Segment Reporting Information [Line Items]
Revenue	8,112	8,015
Net Assets	$ 4,879	$ 2,111