NET INCOME (LOSS) PER SHARE - Schedule of Antidilutive Securities (Details) - shares shares in Thousands	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
EARNINGS PER SHARE
Total	892	5,385
Employee Stock Option
EARNINGS PER SHARE
Total	890	5,343
Restricted Stock Units (RSUs)
EARNINGS PER SHARE
Total	2	2
ESPP
EARNINGS PER SHARE
Total	0	40

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Name:	us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration