INCOME TAXES - Changes in Valuation Allowance for Deferred Tax Assets (Details) - Valuation Allowance, Deferred Tax Asset - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at January 1	$ (12,363)	$ (12,564)	$ (12,220)
Changes due to federal and foreign capital loss carryforwards	(450)	201	(344)
Balance at December 31	$ (12,813)	$ (12,363)	$ (12,564)