SEGMENT AND GEOGRAPHIC DATA Segment Information (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) segments	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | segments			3
Revenue, from external customers	$ 118,108	$ 108,136	$ 335,104	$ 322,430
Inter-segment revenue	0	0	0	0
Total revenue	118,108	108,136	335,104	322,430
Gross margin, from external customers	47,245	43,542	138,003	131,643
Inter-segment gross margin	0	0	0	0
Gross margin	47,245	43,542	138,003	131,643
Business reorganization	477	183	636	964
EBITDA (loss)	475	(280)	2,990	(5,067)
Depreciation and amortization	697	801	2,050	2,294
Intercompany interest income (expense), net	0	0	0	0
Interest income (expense), net	(110)	(109)	(317)	(264)
Income (loss) from continuing operations before provision for income taxes	(332)	(1,190)	623	(7,625)
Accounts receivable, net	71,325	64,930	71,325	64,930	$ 58,517
Long-lived assets, net of accumulated depreciation and amortization	8,155	9,248	8,155	9,248
Total assets	109,807	104,941	109,807	104,941	$ 101,812
Hudson Asia Pacific
Segment Reporting Information [Line Items]
Total revenue	12,653	10,721	33,747	28,542
Long-lived assets, net of accumulated depreciation and amortization	521	384	521	384
Hudson Europe
Segment Reporting Information [Line Items]
Total revenue	13,290	12,356	43,351	39,382
Long-lived assets, net of accumulated depreciation and amortization	323	196	323	196
Operating Segments | Hudson Americas
Segment Reporting Information [Line Items]
Revenue, from external customers	4,044	4,163	12,519	11,660
Inter-segment revenue	47	42	47	21
Total revenue	4,091	4,205	12,566	11,681
Gross margin, from external customers	3,668	3,691	11,239	10,210
Inter-segment gross margin	43	13	35	(11)
Gross margin	3,711	3,704	11,274	10,199
Business reorganization	0	(3)	(91)	(41)
EBITDA (loss)	483	326	1,117	313
Depreciation and amortization	0	12	2	43
Intercompany interest income (expense), net	0	0	0	0
Interest income (expense), net	0	0	0	0
Income (loss) from continuing operations before provision for income taxes	483	314	1,115	270
Accounts receivable, net	2,436	2,937	2,436	2,937
Long-lived assets, net of accumulated depreciation and amortization	0	8	0	8
Total assets	6,317	5,383	6,317	5,383
Operating Segments | Hudson Asia Pacific
Segment Reporting Information [Line Items]
Revenue, from external customers	76,509	64,607	205,483	177,717
Inter-segment revenue	0	0	0	(1)
Total revenue	76,509	64,607	205,483	177,716
Gross margin, from external customers	25,407	22,414	68,573	63,601
Inter-segment gross margin	(63)	(59)	(181)	(182)
Gross margin	25,344	22,355	68,392	63,419
Business reorganization	0	(1)	0	273
EBITDA (loss)	1,685	275	2,253	(370)
Depreciation and amortization	445	457	1,311	1,296
Intercompany interest income (expense), net	0	0	0	0
Interest income (expense), net	(103)	(101)	(314)	(230)
Income (loss) from continuing operations before provision for income taxes	1,137	(283)	628	(1,896)
Accounts receivable, net	40,793	34,806	40,793	34,806
Long-lived assets, net of accumulated depreciation and amortization	6,587	7,364	6,587	7,364
Total assets	58,638	53,778	58,638	53,778
Operating Segments | Hudson Europe
Segment Reporting Information [Line Items]
Revenue, from external customers	37,555	39,366	117,102	133,053
Inter-segment revenue	78	73	206	220
Total revenue	37,633	39,439	117,308	133,273
Gross margin, from external customers	18,170	17,437	58,191	57,832
Inter-segment gross margin	20	46	146	193
Gross margin	18,190	17,483	58,337	58,025
Business reorganization	477	188	749	781
EBITDA (loss)	(380)	(466)	3,117	761
Depreciation and amortization	173	253	501	629
Intercompany interest income (expense), net	(47)	(48)	(136)	(163)
Interest income (expense), net	(2)	(6)	3	(28)
Income (loss) from continuing operations before provision for income taxes	(602)	(773)	2,483	(59)
Accounts receivable, net	28,096	27,187	28,096	27,187
Long-lived assets, net of accumulated depreciation and amortization	1,446	1,431	1,446	1,431
Total assets	42,662	42,978	42,662	42,978
Corporate
Segment Reporting Information [Line Items]
Revenue, from external customers	0	0	0	0
Inter-segment revenue	0	0	0	0
Total revenue	0	0	0	0
Gross margin, from external customers	0	0	0	0
Inter-segment gross margin	0	0	0	0
Gross margin	0	0	0	0
Business reorganization	0	(1)	(22)	(49)
EBITDA (loss)	(1,313)	(415)	(3,497)	(5,771)
Depreciation and amortization	79	79	236	326
Intercompany interest income (expense), net	47	48	136	163
Interest income (expense), net	(5)	(2)	(6)	(6)
Income (loss) from continuing operations before provision for income taxes	(1,350)	(448)	(3,603)	(5,940)
Accounts receivable, net	0	0	0	0
Long-lived assets, net of accumulated depreciation and amortization	122	445	122	445
Total assets	2,190	2,802	2,190	2,802
Elimination
Segment Reporting Information [Line Items]
Revenue, from external customers	0	0	0	0
Inter-segment revenue	(125)	(115)	(253)	(240)
Total revenue	(125)	(115)	(253)	(240)
Gross margin, from external customers	0	0	0	0
Inter-segment gross margin	0	0	0	0
Gross margin	0	0	0	0
Business reorganization	0	0	0	0
EBITDA (loss)	0	0	0	0
Depreciation and amortization	0	0	0	0
Intercompany interest income (expense), net	0	0	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	0	0	0	0
Total assets	$ 0	$ 0	$ 0	$ 0