SEGMENT AND GEOGRAPHIC DATA Segment Information (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) segments	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of Reportable Segments | segments			3
Revenue, from external customers	$ 113,591	$ 113,067	$ 216,996	$ 214,294
Inter-segment revenue	0	0	0	0
Total revenue	113,591	113,067	216,996	214,294
Gross margin, from external customers	48,326	46,839	90,758	88,101
Inter-segment gross margin	0	0	0	0
Gross margin	48,326	46,839	90,758	88,101
Business reorganization	(63)	144	159	781
EBITDA (loss)	2,955	(1,633)	2,515	(4,787)
Depreciation and amortization	687	805	1,353	1,493
Intercompany interest income (expense), net	0	0	0	0
Interest income (expense), net	(119)	(101)	(207)	(155)
Income (loss) from continuing operations before provision for income taxes	2,149	(2,539)	955	(6,435)
Accounts receivable, net	72,147	67,368	72,147	67,368	$ 58,517
Long-lived assets, net of accumulated depreciation and amortization	8,436	9,365	8,436	9,365
Total assets	110,048	115,928	110,048	115,928	$ 101,812
Hudson Asia Pacific
Segment Reporting Information [Line Items]
Total revenue	11,567	9,864	21,092	17,820
Long-lived assets, net of accumulated depreciation and amortization	581	456	581	456
Hudson Europe
Segment Reporting Information [Line Items]
Total revenue	15,849	14,903	30,062	27,025
Long-lived assets, net of accumulated depreciation and amortization	257	180	257	180
Operating Segments | Hudson Americas
Segment Reporting Information [Line Items]
Revenue, from external customers	4,161	3,661	8,475	7,498
Inter-segment revenue	0	(22)	0	(22)
Total revenue	4,161	3,639	8,475	7,476
Gross margin, from external customers	3,735	3,180	7,571	6,520
Inter-segment gross margin	(4)	(25)	(8)	(25)
Gross margin	3,731	3,155	7,563	6,495
Business reorganization	1	(22)	(91)	(38)
EBITDA (loss)	301	(178)	635	(15)
Depreciation and amortization	0	8	2	31
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	301	(186)	633	(46)
Accounts receivable, net	2,378	2,637	2,378	2,637
Long-lived assets, net of accumulated depreciation and amortization	0	20	0	20
Total assets	5,674	5,793	5,674	5,793
Operating Segments | Hudson Asia Pacific
Segment Reporting Information [Line Items]
Revenue, from external customers	69,264	62,039	128,974	113,110
Inter-segment revenue	0	(1)	0	0
Total revenue	69,264	62,038	128,974	113,110
Gross margin, from external customers	23,432	22,416	43,166	41,187
Inter-segment gross margin	(60)	(62)	(119)	(121)
Gross margin	23,372	22,354	43,047	41,066
Business reorganization	0	77	0	274
EBITDA (loss)	1,309	575	617	(656)
Depreciation and amortization	437	435	865	838
Intercompany interest income (expense), net	0	0	0	0
Interest income (expense), net	(116)	(88)	(213)	(128)
Income (loss) from continuing operations before provision for income taxes	756	52	(461)	(1,622)
Accounts receivable, net	39,258	35,272	39,258	35,272
Long-lived assets, net of accumulated depreciation and amortization	6,801	7,323	6,801	7,323
Total assets	57,133	55,990	57,133	55,990
Operating Segments | Hudson Europe
Segment Reporting Information [Line Items]
Revenue, from external customers	40,166	47,367	79,547	93,686
Inter-segment revenue	67	86	129	147
Total revenue	40,233	47,453	79,676	93,833
Gross margin, from external customers	21,159	21,243	40,021	40,394
Inter-segment gross margin	65	87	127	146
Gross margin	21,224	21,330	40,148	40,540
Business reorganization	(64)	109	272	593
EBITDA (loss)	2,612	1,553	3,440	1,223
Depreciation and amortization	171	193	328	376
Intercompany interest income (expense), net	(46)	(58)	(89)	(115)
Interest income (expense), net	0	(9)	6	(23)
Income (loss) from continuing operations before provision for income taxes	2,395	1,293	3,029	709
Accounts receivable, net	30,511	29,459	30,511	29,459
Long-lived assets, net of accumulated depreciation and amortization	1,426	1,506	1,426	1,506
Total assets	44,980	51,663	44,980	51,663
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	(20)	(22)	(48)
EBITDA (loss)	(1,267)	(3,583)	(2,177)	(5,339)
Depreciation and amortization	79	169	158	248
Intercompany interest income (expense), net	46	58	89	115
Interest income (expense), net	(3)	(4)	0	(4)
Income (loss) from continuing operations before provision for income taxes	(1,303)	(3,698)	(2,246)	(5,476)
Accounts receivable, net	0	0	0	0
Long-lived assets, net of accumulated depreciation and amortization	209	516	209	516
Total assets	2,261	2,482	2,261	2,482
Elimination
Segment Reporting Information [Line Items]
Revenue, from external customers	0	0	0	0
Inter-segment revenue	(67)	(63)	(129)	(125)
Total revenue	(67)	(63)	(129)	(125)
Gross margin, from external customers	0	0	0	0
Inter-segment gross margin	(1)	0	0	0
Gross margin	(1)	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
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