SEGMENT AND GEOGRAPHIC DATA Segment Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) segments	Jun. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | segments			3
Revenue	$ 17,015	$ 14,517	$ 33,230	$ 28,472
Gross margin	10,801	10,705	20,955	20,707
Business reorganization	0	1	0	(113)
EBITDA (loss)	(1,302)	(405)	(4,027)	(657)
Depreciation and amortization	2	79	2	160
Segment Reporting Information, Intersegment Interest Income (Expense), Net	0		0
Interest income (expense), net	60	(4)	60	(4)
Income (loss) from continuing operations before provision for income taxes	(1,244)	(488)	(3,969)	(821)
Accounts receivable, net	14,201	10,974	14,201	10,974	$ 11,545
Long-lived assets, net of accumulated depreciation and amortization (b)	5	202	5	202
Total assets	54,522	17,920	54,522	17,920	$ 111,640
Operating Segments | Hudson Americas
Segment Reporting Information [Line Items]
Revenue	3,509	4,161	7,209	8,475
Gross margin	2,923	3,731	6,046	7,571
Business reorganization				(91)
EBITDA (loss)	(76)	301	215	635
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	(76)	301	215	633
Accounts receivable, net	2,605	2,378	2,605	2,378
Long-lived assets, net of accumulated depreciation and amortization (b)	0	0	0	0
Total assets	4,618	5,637	4,618	5,637
Operating Segments | Hudson Asia Pacific
Segment Reporting Information [Line Items]
Revenue	9,600	6,817	18,425	13,159
Gross margin	5,759	4,726	10,682	8,911
Business reorganization				0
EBITDA (loss)	508	1,055	1,052	1,797
Depreciation and amortization	0	0	0	0
Segment Reporting Information, Intersegment Interest Income (Expense), Net	(108)		(108)
Interest income (expense), net	0	0	0	0
Income (loss) from continuing operations before provision for income taxes	400	1,055	944	1,797
Accounts receivable, net	6,787	4,793	6,787	4,793
Long-lived assets, net of accumulated depreciation and amortization (b)	0	0	0	0
Total assets	9,863	5,117	9,863	5,117
Operating Segments | Hudson Europe
Segment Reporting Information [Line Items]
Revenue	3,906	3,539	7,596	6,838
Gross margin	2,119	2,248	4,227	4,225
Business reorganization				1
EBITDA (loss)	34	364	45	541
Depreciation and amortization	2	0	2	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	32	364	43	541
Accounts receivable, net	4,803	3,803	4,803	3,803
Long-lived assets, net of accumulated depreciation and amortization (b)	5	1	5	1
Total assets	8,643	4,868	8,643	4,868
Corporate
Segment Reporting Information [Line Items]
Revenue	0	0	0	0
Gross margin	0	0	0	0
Business reorganization				(23)
EBITDA (loss)	(1,768)	(2,125)	(5,339)	(3,630)
Depreciation and amortization	0	79	0	158
Segment Reporting Information, Intersegment Interest Income (Expense), Net	108		108
Interest income (expense), net	60	(4)	60	(4)
Income (loss) from continuing operations before provision for income taxes	(1,600)	(2,208)	(5,171)	(3,792)
Accounts receivable, net	6	0	6	0
Long-lived assets, net of accumulated depreciation and amortization (b)	0	201	0	201
Total assets	31,398	2,298	31,398	2,298
Inter-Segment Elimination
Segment Reporting Information [Line Items]
Revenue	0	0	0	0
Gross margin	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