SEGMENT AND GEOGRAPHIC DATA - Segment Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2025 USD ($) Segment	Mar. 31, 2024 USD ($)	Dec. 31, 2024 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | Segment	3
Revenue, from external customers	$ 31,866	$ 33,891
Inter-segment revenue	0	0
Revenue	31,866	33,891
Adjusted net revenue, from external customers	16,398	16,330
Inter-segment adjusted net revenue	0	0
Total adjusted net revenue	16,398	16,330
Salaries and related	(14,345)	(15,166)
EBITDA (loss)	(1,512)	(2,682)
Depreciation and amortization	(283)	(397)
Intercompany dividend/interest (expense) income, net	0	0
Interest income, net	71	93
Loss before income taxes	(1,724)	(2,986)
Provision for income taxes	(32)	88
Net loss	(1,756)	(2,898)
Accounts receivable, net	21,281	20,093	$ 20,093
Long-lived assets, net of accumulated depreciation and amortization	8,186	8,436
Total assets	53,185	52,583	$ 52,583
Inter-Segment Elimination
Segment Reporting Information [Line Items]
Revenue, from external customers	0	0
Inter-segment revenue	(91)	(55)
Revenue	(91)	(55)
Adjusted net revenue, from external customers	0	0
Inter-segment adjusted net revenue	0	0
Total adjusted net revenue	0	0
Salaries and related	0
EBITDA (loss)	0	0
Depreciation and amortization	0	0
Intercompany dividend/interest (expense) income, net	0	0
Interest income, net	0	0
Provision for income taxes	0	0
Net loss	0	0
Accounts receivable, net	0	0
Long-lived assets, net of accumulated depreciation and amortization	0	0
Total assets	0	0
Hudson Americas | Operating Segments
Segment Reporting Information [Line Items]
Revenue, from external customers	6,852	5,994
Inter-segment revenue	90	55
Revenue	6,942	6,049
Adjusted net revenue, from external customers	5,980	5,805
Inter-segment adjusted net revenue	89	55
Total adjusted net revenue	6,069	5,860
Salaries and related	(4,818)
EBITDA (loss)	(141)	(864)
Depreciation and amortization	(241)	(349)
Intercompany dividend/interest (expense) income, net	0	0
Interest income, net	0	0
Provision for income taxes	(20)	(15)
Net loss	(402)	(1,228)
Accounts receivable, net	5,643	4,740
Long-lived assets, net of accumulated depreciation and amortization	6,409	6,640
Total assets	14,571	14,455
Hudson Asia Pacific | Operating Segments
Segment Reporting Information [Line Items]
Revenue, from external customers	19,127	21,509
Inter-segment revenue	1	0
Revenue	19,128	21,509
Adjusted net revenue, from external customers	7,211	6,546
Inter-segment adjusted net revenue	(88)	(47)
Total adjusted net revenue	7,123	6,499
Salaries and related	(5,718)
EBITDA (loss)	283	(601)
Depreciation and amortization	(35)	(38)
Intercompany dividend/interest (expense) income, net	(123)	(132)
Interest income, net	2	3
Provision for income taxes	(86)	217
Net loss	41	(551)
Accounts receivable, net	10,801	9,254
Long-lived assets, net of accumulated depreciation and amortization	1,731	1,744
Total assets	22,185	21,425
Hudson Europe | Operating Segments
Segment Reporting Information [Line Items]
Revenue, from external customers	5,887	6,388
Inter-segment revenue	0	0
Revenue	5,887	6,388
Adjusted net revenue, from external customers	3,207	3,979
Inter-segment adjusted net revenue	(1)	(8)
Total adjusted net revenue	3,206	3,971
Salaries and related	(3,358)
EBITDA (loss)	(638)	268
Depreciation and amortization	(4)	(7)
Intercompany dividend/interest (expense) income, net	0	0
Interest income, net	0	0
Provision for income taxes	30	(86)
Net loss	(612)	175
Accounts receivable, net	4,837	6,099
Long-lived assets, net of accumulated depreciation and amortization	21	26
Total assets	9,350	9,393
Corporate Segment | Operating Segments
Segment Reporting Information [Line Items]
Revenue, from external customers	0	0
Inter-segment revenue	0	0
Revenue	0	0
Adjusted net revenue, from external customers	0	0
Inter-segment adjusted net revenue	0	0
Total adjusted net revenue	0	0
Salaries and related	(451)
EBITDA (loss)	(1,016)	(1,485)
Depreciation and amortization	(3)	(3)
Intercompany dividend/interest (expense) income, net	123	132
Interest income, net	69	90
Provision for income taxes	44	(28)
Net loss	(783)	(1,294)
Accounts receivable, net	0	0
Long-lived assets, net of accumulated depreciation and amortization	25	26
Total assets	$ 7,079	$ 7,310