STOCKHOLDERS' EQUITY - Schedule of Compensation Cost on Net Earnings (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Net earnings	$ (6,332)	$ (5,884)	$ (4,965)
Cost of sales
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation cost	1,115	1,147	973
Operating expenses
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation cost	$ 7,188	$ 6,449	$ 5,440

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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