Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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STOCK-BASED COMPENSATION - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 2.3
Unrecognized compensation expense, recognized period	8 months 12 days
Fair value of vested awards	$ 1.2	$ 2.0
Restricted Stock Awards \| Employees and Executive Officers
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Restricted Stock Awards \| Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
2018 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized for grant (shares)			15,000,000
Shares available for future awards (shares)	12,563,710
2013 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for future awards (shares)	769,775