INCOME TAXES - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2023	Dec. 31, 2022
Operating Loss Carryforwards [Line Items]
Valuation allowance		$ (24,105)	$ (22,570)
Valuation allowance related to NOL carryforwards		9,300
Contribution to Blue Foundry Charitable Foundation	$ 9,000
Approximate amount of retained earnings for which no provision for income tax has been made		14,600	$ 14,600
Charitable Contribution
Operating Loss Carryforwards [Line Items]
Charitable contribution tax credit carryforward, term	5 years
Domestic Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards		33,000
State and Local Jurisdiction | New Jersey Division of Taxation
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards		$ 33,000
Expiration term on state operating loss carryforwards		18 years