FAIR VALUE MEASUREMENTS - Fair value hierarchy for assets and liabilities measured at fair value (Details) - Recurring $ in Thousands	Dec. 31, 2020 USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total	$ (1,690)
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrant liability	$ (1,690)

The fair value of shares that would be issued, determined under the conditions specified in the contract if the settlement were to occur at the reporting date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 480
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109262807&loc=d3e22047-110879

Name:	us-gaap_SharesSubjectToMandatoryRedemptionSettlementTermsFairValueOfShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant