SEGMENT AND GEOGRAPHIC DATA Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) segments	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | segments			3
Revenue	$ 17,127	$ 15,898	$ 50,357	$ 44,371
Gross profit	10,881	11,170	31,836	31,879
Business reorganization	0	0	0	(112)
EBITDA (loss)	(812)	59	(4,839)	(597)
Depreciation and amortization	1	79	3	238
Segment Reporting Information, Intersegment Interest Income (Expense), Net	0		0
Interest income (expense), net	102	(3)	162	(7)
Income (loss) from continuing operations before provision for income taxes	(711)	(23)	(4,680)	(842)
Accounts receivable, net	14,500	11,117	14,500	11,117	$ 11,545
Long-lived assets, net of accumulated depreciation and amortization (b)	157	131	157	131
Total assets	54,436	18,647	54,436	18,647	$ 111,640
Operating Segments | Hudson Americas
Segment Reporting Information [Line Items]
Revenue	3,590	4,091	10,799	12,566
Gross profit	2,990	3,711	9,039	11,274
Business reorganization				(91)
EBITDA (loss)	87	483	303	1,117
Depreciation and amortization	0	0	0	2
Segment Reporting Information, Intersegment Interest Income (Expense), Net	0		0
Interest income (expense), net	0	0	0	0
Income (loss) from continuing operations before provision for income taxes	87	483	303	1,115
Accounts receivable, net	2,428	2,436	2,428	2,436
Long-lived assets, net of accumulated depreciation and amortization (b)	51	0	51	0
Total assets	4,511	6,317	4,511	6,317
Operating Segments | Hudson Asia Pacific
Segment Reporting Information [Line Items]
Revenue	9,306	8,081	27,731	21,240
Gross profit	5,741	5,173	16,423	14,084
Business reorganization				0
EBITDA (loss)	460	1,379	1,511	3,173
Depreciation and amortization	0	0	0	0
Segment Reporting Information, Intersegment Interest Income (Expense), Net	(105)		(212)
Interest income (expense), net	0	0	0	0
Income (loss) from continuing operations before provision for income taxes	355	1,379	1,299	3,173
Accounts receivable, net	7,653	4,919	7,653	4,919
Long-lived assets, net of accumulated depreciation and amortization (b)	41	0	41	0
Total assets	11,230	5,247	11,230	5,247
Operating Segments | Hudson Europe
Segment Reporting Information [Line Items]
Revenue	4,231	3,773	11,827	10,612
Gross profit	2,150	2,286	6,374	6,521
Business reorganization				1
EBITDA (loss)	(226)	315	(176)	868
Depreciation and amortization	1	0	3	0
Segment Reporting Information, Intersegment Interest Income (Expense), Net	0		0
Interest income (expense), net	0	0	0	0
Income (loss) from continuing operations before provision for income taxes	(227)	315	(179)	868
Accounts receivable, net	4,419	3,762	4,419	3,762
Long-lived assets, net of accumulated depreciation and amortization (b)	56	1	56	1
Total assets	8,689	4,858	8,689	4,858
Corporate
Segment Reporting Information [Line Items]
Revenue	0	0	61	0
Gross profit	0	0	0	0
Business reorganization				(22)
EBITDA (loss)	(1,133)	(2,118)	(6,477)	(5,755)
Depreciation and amortization	0	79	0	236
Segment Reporting Information, Intersegment Interest Income (Expense), Net	105		212
Interest income (expense), net	102	(3)	162	(7)
Income (loss) from continuing operations before provision for income taxes	(926)	(2,200)	(6,103)	(5,998)
Accounts receivable, net	0	0	0	0
Long-lived assets, net of accumulated depreciation and amortization (b)	9	130	9	130
Total assets	30,006	2,225	30,006	2,225
Inter-Segment Elimination
Segment Reporting Information [Line Items]
Revenue	0	(47)	(61)	(47)
Gross profit	0	0	0	0
Business reorganization				0
EBITDA (loss)	0	0	0	0
Depreciation and amortization	0	0	0	0
Segment Reporting Information, Intersegment Interest Income (Expense), Net	0		0
Interest income (expense), net	0	0	0	0
Income (loss) from continuing operations before provision for income taxes	0	0	0	0
Accounts receivable, net	0	0	0	0
Long-lived assets, net of accumulated depreciation and amortization (b)	0	0	0	0
Total assets	$ 0	$ 0	$ 0	$ 0