STOCKHOLDERS' EQUITY AND SHARE-BASED COMPENSATION PLANS - ESPP Activity (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense recognized	$ 1,564	$ 1,996	$ 2,887	$ 4,132
Remaining share-based compensation expense			2,887	4,132
ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deductions from employees			62	48
Share-based compensation expense recognized			46	57
Remaining share-based compensation expense			$ 144	$ 135