NET INCOME (LOSS) PER COMMON SHARE - Disclosure of Anti-Dilutive Shares (Details) - $ / shares shares in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excluded shares as anti-dilutive when reporting a net loss	0	70	2,317	133
Price range of options: from (in dollars per share)			$ 0.40
Price range of options: to (in dollars per share)			$ 13.98
RSUs with service conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excluded shares as anti-dilutive when reporting a net loss	1,393	2,497	353	2,708
Share-based Payment Arrangement, Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excluded shares as anti-dilutive when reporting a net loss	609	609	609	609
Price range of options: from (in dollars per share)	$ 3.54	$ 3.54	$ 3.54	$ 3.54
Price range of options: to (in dollars per share)	$ 13.98	$ 13.98	$ 13.98	$ 13.98
RSUs \| RSUs excluded with service and market conditions as market conditions not met
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excluded shares as anti-dilutive when reporting a net loss	0	199	0	199

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

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- Definition

The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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