PROPERTY AND EQUIPMENT - Schedule of Property and Equipment (Details) - Q1 - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 34	$ 34	$ 26
Accumulated depreciation	(27)	(26)	(22)
Property and equipment, net	7	8	4
Computer equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	21	21	13
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 13	$ 13	$ 13

Amount after accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-SubTopic 10
-Topic 360
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482099/360-10-50-1

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 852
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481372/852-10-55-10

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(8))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479440/944-210-S99-1

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 360
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480842/942-360-50-1

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