Note 9 - NET LOSS PER SHARE - Anti-dilutive Securities (Details) - shares shares in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Anti-dilutive securities (in shares)	774	1,165	937	1,253
Share-based Payment Arrangement, Option [Member]
Anti-dilutive securities (in shares)	45	194	73	209
Restricted Stock Units (RSUs) [Member]
Anti-dilutive securities (in shares)	684	970	795	1,038
Employee Stock Purchase Plan [Member]
Anti-dilutive securities (in shares)	45	1	69	6

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=124432515&loc=d3e3550-109257

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