STOCKHOLDERS' EQUITY AND SHARE-BASED COMPENSATION PLANS - ESPP Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense recognized	$ 7,338	$ 13,824
Remaining share-based compensation expense	7,338	13,824
Proceeds received by the Company for ESPP	$ 98	205
Employee Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance under ESPP (in shares)	33,463
Employee Stock \| 2014 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deductions from employees	$ 70	221
Share-based compensation expense recognized	95	138
Remaining share-based compensation expense	206	464
Proceeds received by the Company for ESPP	$ 98	$ 205
Weighted-average purchase price per common share (in dollars per share)	$ 12.25	$ 45.30
Number of shares purchased by employees under ESPP (in shares)	8,000	4,539

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