STOCKHOLDERS' EQUITY AND SHARE-BASED COMPENSATION PLANS - ESPP Activity (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense recognized	$ 1,606	$ 1,634	$ 4,493	$ 5,762
Remaining share-based compensation expense			4,493	5,762
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deductions from employees			116	113
Share-based compensation expense recognized			70	75
Remaining share-based compensation expense			$ 113	$ 116