SEGMENT AND GEOGRAPHIC DATA - Segment Information (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($)	Mar. 31, 2024 USD ($) segments	Mar. 31, 2024 USD ($) Segment	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments		3	3
Revenue, from external customers	$ 33,891			$ 43,072
Inter-segment revenue	0			0
Revenue	33,891			43,072
Adjusted net revenue, from external customers	16,330			21,764
Inter-segment adjusted net revenue	0			0
Total adjusted net revenue	16,330			21,764
EBITDA (loss)	(2,682)			499
Depreciation and amortization	(397)			(348)
Intercompany dividend/interest (expense) income, net	0			0
Interest income, net	93			64
(Loss) income before income taxes	(2,986)			215
Provision for income taxes	88			139
Net (loss) income	(2,898)			354
Accounts receivable, net	20,970	$ 20,970	$ 20,970	19,710	$ 19,710
Long-lived assets, net of accumulated depreciation and amortization	9,381	9,381	9,381	9,798
Total assets	59,202	59,202	59,202	60,958	$ 60,958
Inter-Segment Elimination
Segment Reporting Information [Line Items]
Revenue, from external customers	0			0
Inter-segment revenue	(55)			15
Revenue	(55)			15
Adjusted net revenue, from external customers	0			0
Inter-segment adjusted net revenue	0			3
Total adjusted net revenue	0			3
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) income	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
Hudson Americas | Operating Segments
Segment Reporting Information [Line Items]
Revenue, from external customers	5,994			9,272
Inter-segment revenue	55			9
Revenue	6,049			9,281
Adjusted net revenue, from external customers	5,805			8,922
Inter-segment adjusted net revenue	55			9
Total adjusted net revenue	5,860			8,931
EBITDA (loss)	(864)			(430)
Depreciation and amortization	(349)			(311)
Intercompany dividend/interest (expense) income, net	0			0
Interest income, net	0			0
Provision for income taxes	(15)			228
Net (loss) income	(1,228)			(513)
Accounts receivable, net	4,677	4,677	4,677	5,502
Long-lived assets, net of accumulated depreciation and amortization	7,423	7,423	7,423	7,773
Total assets	16,223	16,223	16,223	17,632
Hudson Asia Pacific | Operating Segments
Segment Reporting Information [Line Items]
Revenue, from external customers	21,509			27,276
Inter-segment revenue	0			0
Revenue	21,509			27,276
Adjusted net revenue, from external customers	6,546			8,459
Inter-segment adjusted net revenue	(47)			20
Total adjusted net revenue	6,499			8,479
EBITDA (loss)	(601)			1,434
Depreciation and amortization	(38)			(27)
Intercompany dividend/interest (expense) income, net	(132)			(120)
Interest income, net	3			2
Provision for income taxes	217			(368)
Net (loss) income	(551)			921
Accounts receivable, net	11,654	11,654	11,654	9,280
Long-lived assets, net of accumulated depreciation and amortization	1,896	1,896	1,896	1,954
Total assets	23,655	23,655	23,655	23,604
Hudson Europe | Operating Segments
Segment Reporting Information [Line Items]
Revenue, from external customers	6,388			6,524
Inter-segment revenue	0			(24)
Revenue	6,388			6,500
Adjusted net revenue, from external customers	3,979			4,383
Inter-segment adjusted net revenue	(8)			(32)
Total adjusted net revenue	3,971			4,351
EBITDA (loss)	268			444
Depreciation and amortization	(7)			(7)
Intercompany dividend/interest (expense) income, net	0			0
Interest income, net	0			0
Provision for income taxes	(86)			(114)
Net (loss) income	175			323
Accounts receivable, net	4,639	4,639	4,639	4,928
Long-lived assets, net of accumulated depreciation and amortization	26	26	26	33
Total assets	11,424	11,424	11,424	11,064
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
EBITDA (loss)	(1,485)			(949)
Depreciation and amortization	(3)			(3)
Intercompany dividend/interest (expense) income, net	132			120
Interest income, net	90			62
Provision for income taxes	(28)			393
Net (loss) income	(1,294)			(377)
Accounts receivable, net	0	0	0	0
Long-lived assets, net of accumulated depreciation and amortization	36	36	36	38
Total assets	$ 7,900	$ 7,900	$ 7,900	$ 8,658